configs: am335x_evm: Do not disable DM_USB in SPL

DM_USB is now supported in the SPL. Do not undef it
Besides to support DM_USB in SPL, one now has to use SPL_DM_USB

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
1 file changed