Change wifi example to build only DISCO_L475VG_IOT01A
Change wifi example to build only DISCO_L475VG_IOT01A

Currently mbed-os-example-blinky and mbed-os-example-wifi are built for each and every target in Mbed OS. This will change that only DISCO_L475VG_IOT01A is built for mbed-os-example-wifi. DISCO_L475VG_IOT01A was chosen as its one of the wi-fi supported boards and having integrated wi-fi.

mbedmicro/mbed,kjbracey-arm/mbed,mbedmicro/mbed,kjbracey-arm/mbed,mbedmicro/mbed,andcor02/mbed-os,andcor02/mbed-os,kjbracey-arm/mbed,andcor02/mbed-os,kjbracey-arm/mbed,mbedmicro/mbed,andcor02/mbed-os,andcor02/mbed-os,mbedmicro/mbed,andcor02/mbed-os