net: stats: Activate RPL and MLD stats if needed
net: stats: Activate RPL and MLD stats if needed

If user has enabled RPL and STATISTICS, then enable RPL
statistics by default as that is probably what user want.
Same thing for MLD statistics.

Signed-off-by: Jukka Rissanen <f9f077d1da4c7aa947f9864fa5a28c3588f6a45d@linux.intel.com>

mbolivar/zephyr,GiulianoFranchetto/zephyr,galak/zephyr,mbolivar/zephyr,GiulianoFranchetto/zephyr,nashif/zephyr,fbsder/zephyr,holtmann/zephyr,pklazy/zephyr,sharronliu/zephyr,aceofall/zephyr-iotos,sharronliu/zephyr,finikorg/zephyr,Vudentz/zephyr,holtmann/zephyr,bigdinotech/zephyr,nashif/zephyr,pklazy/zephyr,punitvara/zephyr,pklazy/zephyr,fbsder/zephyr,rsalveti/zephyr,holtmann/zephyr,runchip/zephyr-cc3220,bigdinotech/zephyr,fractalclone/zephyr-riscv,nashif/zephyr,zephyrproject-rtos/zephyr,punitvara/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,sharronliu/zephyr,fractalclone/zephyr-riscv,bigdinotech/zephyr,zephyriot/zephyr,aceofall/zephyr-iotos,explora26/zephyr,GiulianoFranchetto/zephyr,ldts/zephyr,pklazy/zephyr,nashif/zephyr,bigdinotech/zephyr,Vudentz/zephyr,aceofall/zephyr-iotos,punitvara/zephyr,rsalveti/zephyr,zephyriot/zephyr,galak/zephyr,fbsder/zephyr,kraj/zephyr,ldts/zephyr,bigdinotech/zephyr,ldts/zephyr,Vudentz/zephyr,finikorg/zephyr,runchip/zephyr-cc3220,pklazy/zephyr,runchip/zephyr-cc3220,mbolivar/zephyr,zephyrproject-rtos/zephyr,aceofall/zephyr-iotos,kraj/zephyr,rsalveti/zephyr,mbolivar/zephyr,galak/zephyr,finikorg/zephyr,ldts/zephyr,Vudentz/zephyr,kraj/zephyr,fractalclone/zephyr-riscv,fractalclone/zephyr-riscv,mbolivar/zephyr,rsalveti/zephyr,kraj/zephyr,fbsder/zephyr,fractalclone/zephyr-riscv,zephyrproject-rtos/zephyr,zephyriot/zephyr,punitvara/zephyr,zephyriot/zephyr,galak/zephyr,punitvara/zephyr,holtmann/zephyr,zephyrproject-rtos/zephyr,zephyriot/zephyr,finikorg/zephyr,finikorg/zephyr,runchip/zephyr-cc3220,explora26/zephyr,aceofall/zephyr-iotos,Vudentz/zephyr,sharronliu/zephyr,fbsder/zephyr,holtmann/zephyr,GiulianoFranchetto/zephyr,explora26/zephyr,rsalveti/zephyr,sharronliu/zephyr,zephyrproject-rtos/zephyr,kraj/zephyr,galak/zephyr,ldts/zephyr,runchip/zephyr-cc3220,explora26/zephyr,explora26/zephyr,nashif/zephyr