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/tao3530_defconfig b/configs/tao3530_defconfig
index d70d840..daca05e 100644
--- a/configs/tao3530_defconfig
+++ b/configs/tao3530_defconfig
@@ -25,6 +25,7 @@
 CONFIG_MTDIDS_DEFAULT="nand0=nand"
 CONFIG_MTDPARTS_DEFAULT="mtdparts=nand:512k(x-loader),1920k(u-boot),128k(u-boot-env),4m(kernel),-(fs)"
 CONFIG_ENV_IS_IN_NAND=y
+CONFIG_TWL4030_LED=y
 CONFIG_MMC_OMAP_HS=y
 CONFIG_NAND=y
 CONFIG_SYS_NAND_BUSWIDTH_16BIT=y