Input: lpc32xx-keys - select INPUT_MATRIXKMAP

This adds a "select" dependency of KEYBOARD_LPC32XX on INPUT_MATRIXKMAP,
as the other drivers are doing in this regard. This fixes the following
compile error if KEYBOARD_LPC32XX is enabled but INPUT_MATRIXKMAP is not:

drivers/input/keyboard/lpc32xx-keys.c:230: undefined reference to
`matrix_keypad_build_keymap'

Signed-off-by: Roland Stigge <stigge@antcom.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index b4b65af..de08740 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -335,6 +335,7 @@
 config KEYBOARD_LPC32XX
 	tristate "LPC32XX matrix key scanner support"
 	depends on ARCH_LPC32XX && OF
+	select INPUT_MATRIXKMAP
 	help
 	  Say Y here if you want to use NXP LPC32XX SoC key scanner interface,
 	  connected to a key matrix.