Change matrix-keymap helper to be out-of-line, like sparse keymap,
allow the helper perform basic keymap validation and return errors,
and prepare for device tree support.
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

This driver adds support for the keypad part of the LM8333 and is
prepared for possible GPIO/PWM drivers. Note that this is not a MFD
because you cannot disable the keypad functionality which, thus,
has to be handled by the core anyhow.
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>