Convert CONFIG_LCD to Kconfig

This converts the following to Kconfig:
   CONFIG_LCD

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Jagan Teki <jteki@openedev.com>
diff --git a/configs/sama5d3xek_mmc_defconfig b/configs/sama5d3xek_mmc_defconfig
index 9573eff..e447955 100644
--- a/configs/sama5d3xek_mmc_defconfig
+++ b/configs/sama5d3xek_mmc_defconfig
@@ -31,4 +31,5 @@
 CONFIG_USB_STORAGE=y
 CONFIG_USB_GADGET=y
 CONFIG_USB_GADGET_ATMEL_USBA=y
+CONFIG_LCD=y
 CONFIG_OF_LIBFDT=y