Small cleanup to SPI write16 and write32 for big-endian
Small cleanup to SPI write16 and write32 for big-endian

Merge a common line.

hallard/Arduino,hallard/Arduino,jes/Arduino,esp8266/Arduino,sticilface/Arduino,wemos/Arduino,jes/Arduino,Lan-Hekary/Arduino,Juppit/Arduino,sticilface/Arduino,Adam5Wu/Arduino,lrmoreno007/Arduino,wemos/Arduino,sticilface/Arduino,hallard/Arduino,sticilface/Arduino,wemos/Arduino,Adam5Wu/Arduino,me-no-dev/Arduino,esp8266/Arduino,jes/Arduino,lrmoreno007/Arduino,Lan-Hekary/Arduino,hallard/Arduino,wemos/Arduino,Lan-Hekary/Arduino,esp8266/Arduino,wemos/Arduino,Juppit/Arduino,Juppit/Arduino,me-no-dev/Arduino,Juppit/Arduino,Lan-Hekary/Arduino,jes/Arduino,Adam5Wu/Arduino,Juppit/Arduino,lrmoreno007/Arduino,Adam5Wu/Arduino,Lan-Hekary/Arduino,me-no-dev/Arduino,lrmoreno007/Arduino,sticilface/Arduino,lrmoreno007/Arduino,Adam5Wu/Arduino,jes/Arduino,hallard/Arduino,esp8266/Arduino,esp8266/Arduino,me-no-dev/Arduino,me-no-dev/Arduino