machine/mpc8313erdb: Change uboot_extra_env USE flag to new syntax
machine/mpc8313erdb: Change uboot_extra_env USE flag to new syntax

esben/base,hundeboll/base,sknsean/base,oe-lite/base,kimrhh/base,hundeboll/base,moths/base,esben/base,sknsean/base,hundeboll/base,kimrhh/base,esben/base,esben/base,kimrhh/base,kimrhh/base,moths/base,sknsean/base,esben/base,oe-lite-rpi/base,hundeboll/base,jacobbarsoe/rpi-base,kimrhh/base,sknsean/base,jacobbarsoe/rpi-base,moths/base,hundeboll/base,hundeboll/base,diorcety/oe-lite-base,sknsean/base,oe-lite/base,moths/base,oe-lite/base,diorcety/oe-lite-base,kimrhh/base,moths/base,sknsean/base,moths/base,oe-lite/base,esben/base,oe-lite/base,oe-lite/base,oe-lite-rpi/base