Convert CONFIG_ATMEL_HLCD to Kconfig

This converts the following to Kconfig:
   CONFIG_ATMEL_HLCD

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/at91sam9n12ek_mmc_defconfig b/configs/at91sam9n12ek_mmc_defconfig
index 6f159aa..5a147a0 100644
--- a/configs/at91sam9n12ek_mmc_defconfig
+++ b/configs/at91sam9n12ek_mmc_defconfig
@@ -61,4 +61,5 @@
 CONFIG_USB=y
 CONFIG_DM_USB=y
 CONFIG_USB_STORAGE=y
+CONFIG_ATMEL_HLCD=y
 CONFIG_LCD=y