This is defined in the asm/cache.h header file. Update this header file to
include it so it gets the same value consistently across U-Boot.
This fixes 'usb host' on omapl138_lcdk.
Fixes: 90526e9fbac ("common: Drop net.h from common header") Reported-by: Adam Ford <aford173@gmail.com> Signed-off-by: Simon Glass <sjg@chromium.org> Tested-by: Adam Ford <aford173@gmail.com> Reviewed-by: Tom Rini <trini@konsulko.com>