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/rpi_defconfig b/configs/rpi_defconfig
index d912945..ba64c7c 100644
--- a/configs/rpi_defconfig
+++ b/configs/rpi_defconfig
@@ -22,5 +22,6 @@
 CONFIG_CMD_FS_GENERIC=y
 CONFIG_USB=y
 CONFIG_USB_STORAGE=y
+CONFIG_LCD=y
 CONFIG_PHYS_TO_BUS=y
 CONFIG_OF_LIBFDT=y