[MINOR][DOCS] Fix src/dest type documentation for `to_timestamp`
[MINOR][DOCS] Fix src/dest type documentation for `to_timestamp`

### What changes were proposed in this pull request?

Minor documentation fix

### Why are the changes needed?

### Does this PR introduce any user-facing change?

### How was this patch tested?

Manually; consider adding tests?

Closes #27295 from deepyaman/patch-2.

Authored-by: Deepyaman Datta <ae9c33d1937cc7cdfa5163e08a7b3e588940cc1a@utexas.edu>
Signed-off-by: HyukjinKwon <2680965ad5aae29275c8fb10150cb10f5554e78b@apache.org>

apache/spark,shuangshuangwang/spark,darionyaphet/spark,wzhfy/spark,zero323/spark,gengliangwang/spark,mahak/spark,WeichenXu123/spark,zero323/spark,zuotingbing/spark,maropu/spark,dongjoon-hyun/spark,cloud-fan/spark,JoshRosen/spark,milliman/spark,JoshRosen/spark,maropu/spark,HyukjinKwon/spark,ConeyLiu/spark,WeichenXu123/spark,goldmedal/spark,wzhfy/spark,jiangxb1987/spark,apache/spark,zzcclp/spark,WeichenXu123/spark,chuckchen/spark,shuangshuangwang/spark,chuckchen/spark,ConeyLiu/spark,spark-test/spark,wzhfy/spark,zuotingbing/spark,cloud-fan/spark,jiangxb1987/spark,jiangxb1987/spark,rednaxelafx/apache-spark,dbtsai/spark,BryanCutler/spark,skonto/spark,goldmedal/spark,srowen/spark,wangmiao1981/spark,ueshin/apache-spark,gengliangwang/spark,chuckchen/spark,HyukjinKwon/spark,hvanhovell/spark,cloud-fan/spark,ueshin/apache-spark,chuckchen/spark,apache/spark,mahak/spark,skonto/spark,HyukjinKwon/spark,JoshRosen/spark,wangyum/spark,ueshin/apache-spark,holdenk/spark,spark-test/spark,goldmedal/spark,ptkool/spark,goldmedal/spark,xuanyuanking/spark,wangyum/spark,srowen/spark,jiangxb1987/spark,wangmiao1981/spark,HyukjinKwon/spark,holdenk/spark,cloud-fan/spark,kevinyu98/spark,wzhfy/spark,taroplus/spark,wangmiao1981/spark,nchammas/spark,srowen/spark,wangyum/spark,dongjoon-hyun/spark,dbtsai/spark,darionyaphet/spark,wzhfy/spark,milliman/spark,holdenk/spark,mahak/spark,rednaxelafx/apache-spark,srowen/spark,ConeyLiu/spark,gengliangwang/spark,holdenk/spark,darionyaphet/spark,rednaxelafx/apache-spark,ptkool/spark,ueshin/apache-spark,zero323/spark,zuotingbing/spark,vinodkc/spark,kevinyu98/spark,rednaxelafx/apache-spark,dongjoon-hyun/spark,shaneknapp/spark,rednaxelafx/apache-spark,cloud-fan/spark,HyukjinKwon/spark,apache/spark,taroplus/spark,ptkool/spark,hvanhovell/spark,srowen/spark,wangmiao1981/spark,ConeyLiu/spark,ueshin/apache-spark,ptkool/spark,xuanyuanking/spark,ueshin/apache-spark,milliman/spark,zzcclp/spark,wangyum/spark,witgo/spark,witgo/spark,cloud-fan/spark,ptkool/spark,kevinyu98/spark,cloud-fan/spark,zuotingbing/spark,WeichenXu123/spark,kevinyu98/spark,skonto/spark,witgo/spark,vinodkc/spark,skonto/spark,nchammas/spark,WeichenXu123/spark,shuangshuangwang/spark,spark-test/spark,taroplus/spark,kevinyu98/spark,maropu/spark,HyukjinKwon/spark,gengliangwang/spark,milliman/spark,JoshRosen/spark,holdenk/spark,taroplus/spark,dbtsai/spark,spark-test/spark,spark-test/spark,mahak/spark,hvanhovell/spark,zzcclp/spark,skonto/spark,zero323/spark,shaneknapp/spark,maropu/spark,witgo/spark,nchammas/spark,vinodkc/spark,rednaxelafx/apache-spark,vinodkc/spark,hvanhovell/spark,xuanyuanking/spark,jiangxb1987/spark,gengliangwang/spark,hvanhovell/spark,zzcclp/spark,WeichenXu123/spark,apache/spark,ConeyLiu/spark,gengliangwang/spark,nchammas/spark,wangmiao1981/spark,rednaxelafx/apache-spark,vinodkc/spark,xuanyuanking/spark,holdenk/spark,darionyaphet/spark,ptkool/spark,spark-test/spark,skonto/spark,JoshRosen/spark,zuotingbing/spark,milliman/spark,kevinyu98/spark,matthewfranglen/spark,BryanCutler/spark,taroplus/spark,BryanCutler/spark,wangmiao1981/spark,shaneknapp/spark,shaneknapp/spark,shaneknapp/spark,dongjoon-hyun/spark,shuangshuangwang/spark,JoshRosen/spark,dongjoon-hyun/spark,dongjoon-hyun/spark,hvanhovell/spark,chuckchen/spark,darionyaphet/spark,zuotingbing/spark,zero323/spark,ptkool/spark,goldmedal/spark,goldmedal/spark,dongjoon-hyun/spark,nchammas/spark,BryanCutler/spark,witgo/spark,darionyaphet/spark,maropu/spark,gengliangwang/spark,wangyum/spark,skonto/spark,wangyum/spark,chuckchen/spark,jiangxb1987/spark,xuanyuanking/spark,zzcclp/spark,kevinyu98/spark,zzcclp/spark,milliman/spark,ConeyLiu/spark,wzhfy/spark,HyukjinKwon/spark,zzcclp/spark,chuckchen/spark,JoshRosen/spark,nchammas/spark,witgo/spark,BryanCutler/spark,dbtsai/spark,goldmedal/spark,shaneknapp/spark,ueshin/apache-spark,wangyum/spark,taroplus/spark,hvanhovell/spark,spark-test/spark,dbtsai/spark,apache/spark,taroplus/spark,zero323/spark,xuanyuanking/spark,dbtsai/spark,holdenk/spark,apache/spark,witgo/spark,mahak/spark,zero323/spark,shaneknapp/spark,nchammas/spark,shuangshuangwang/spark,maropu/spark,xuanyuanking/spark,srowen/spark,maropu/spark,wangmiao1981/spark,wzhfy/spark,jiangxb1987/spark,darionyaphet/spark,srowen/spark,BryanCutler/spark,vinodkc/spark,vinodkc/spark,shuangshuangwang/spark,zuotingbing/spark,dbtsai/spark,mahak/spark,milliman/spark,WeichenXu123/spark,ConeyLiu/spark,BryanCutler/spark,shuangshuangwang/spark,mahak/spark