ARM: imx: cm_fx6: defconfig: enable CONFIG_DM_KEYBOARD

ARM: imx: cm_fx6: defconfig: enable CONFIG_DM_KEYBOARD

Commit 5248930ebf48 ("dm: imx: cm_fx6: Enable more driver model support")
enabled driver model support for USB. But it missed to enable driver
model support for keyboards. As a result, USB keyboards do no longer
work.

Fix this by enabling driver model support for keyboards.

Fixes: 5248930ebf48 ("dm: imx: cm_fx6: Enable more driver model support")
Signed-off-by: Christopher Spinrath <[email protected]>
Reviewed-by: Fabio Estevam <[email protected]>
Reviewed-by: Simon Glass <[email protected]>