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/sniper_defconfig b/configs/sniper_defconfig
index 8ba6bc4..269d59e 100644
--- a/configs/sniper_defconfig
+++ b/configs/sniper_defconfig
@@ -26,6 +26,7 @@
 CONFIG_FASTBOOT_FLASH=y
 CONFIG_FASTBOOT_FLASH_MMC_DEV=0
 CONFIG_SYS_OMAP24_I2C_SPEED=400000
+CONFIG_TWL4030_INPUT=y
 CONFIG_MMC_OMAP_HS=y
 CONFIG_CONS_INDEX=3
 CONFIG_SYS_NS16550=y