Convert CONFIG_TWL4030_LED et al to Kconfig

This converts the following to Kconfig:
   CONFIG_TWL4030_LED
   CONFIG_TWL4030_INPUT

This also removes dead references to:
   CONFIG_TWL4030_KEYPAD

Signed-off-by: Adam Ford <aford173@gmail.com>
diff --git a/configs/cairo_defconfig b/configs/cairo_defconfig
index c7124cf..5c64d69 100644
--- a/configs/cairo_defconfig
+++ b/configs/cairo_defconfig
@@ -27,6 +27,7 @@
 CONFIG_CMD_EXT4_WRITE=y
 CONFIG_CMD_MTDPARTS=y
 CONFIG_ENV_IS_IN_NAND=y
+CONFIG_TWL4030_LED=y
 CONFIG_MMC_OMAP_HS=y
 CONFIG_NAND=y
 CONFIG_SPL_NAND_SIMPLE=y