Input: add generic GPIO-tilt driver

There exist tilt switches that simply report their tilt-state via
some gpios. The number and orientation of their axes can vary
depending on the switch used and the build of the device. Also two
or more one-axis switches could be combined to provide multi-dimensional
orientation.

One example of a device using such a switch is the family of Qisda
ebook readers, where the switch provides information about the
landscape / portrait orientation of the device. The example in
Documentation/input/gpio-tilt.txt documents exactly this one-axis
device.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index a244fc6..90070c1 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -23,6 +23,7 @@
 obj-$(CONFIG_INPUT_COBALT_BTNS)		+= cobalt_btns.o
 obj-$(CONFIG_INPUT_DM355EVM)		+= dm355evm_keys.o
 obj-$(CONFIG_HP_SDC_RTC)		+= hp_sdc_rtc.o
+obj-$(CONFIG_INPUT_GPIO_TILT_POLLED)	+= gpio_tilt_polled.o
 obj-$(CONFIG_INPUT_IXP4XX_BEEPER)	+= ixp4xx-beeper.o
 obj-$(CONFIG_INPUT_KEYSPAN_REMOTE)	+= keyspan_remote.o
 obj-$(CONFIG_INPUT_KXTJ9)		+= kxtj9.o