ARM: imx: cm_fx6: defconfig: enable CONFIG_DM_KEYBOARD

Commit 5248930e ("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: 5248930e ("dm: imx: cm_fx6: Enable more driver model support")
Signed-off-by: Christopher Spinrath <christopher.spinrath@rwth-aachen.de>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

configs/cm_fx6_defconfig

@@ -53,6 +53,7 @@ CONFIG_MTDPARTS_DEFAULT="mtdparts=spi0.0:768k(uboot),256k(uboot-environment),-(r
 CONFIG_OF_CONTROL=y
 CONFIG_ENV_IS_IN_SPI_FLASH=y
 CONFIG_DWC_AHSATA=y
+CONFIG_DM_KEYBOARD=y
 CONFIG_DM_MMC=y
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_ATMEL=y