Input: introduce lm8323 keypad driver

lm8323 is the keypad driver used in n810 device.

[akpm@linux-foundation.org: coding-style fixes]
[dtor@mail.ru: various cleanups]
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Reviewed-by: Trilok Soni <soni.trilok@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>