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/omap3_beagle_defconfig b/configs/omap3_beagle_defconfig
index f26f5ad..0a402cc 100644
--- a/configs/omap3_beagle_defconfig
+++ b/configs/omap3_beagle_defconfig
@@ -50,6 +50,7 @@
 CONFIG_LED_STATUS_GREEN_ENABLE=y
 CONFIG_LED_STATUS_GREEN=2
 CONFIG_LED_STATUS_CMD=y
+CONFIG_TWL4030_LED=y
 CONFIG_MMC_OMAP_HS=y
 CONFIG_NAND=y
 CONFIG_SYS_NAND_BUSWIDTH_16BIT=y