uboot-imx

rpi: Enable USB keyboard support

This is currently disabled, so USB keyboards are not detected in U-Boot.
Enable this option to fix that.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Jonathan Gray <jsg@jsg.id.au>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Paul Barker <pbarker@toganlabs.com>