Input: matrix_keypad - add option to drive inactive columns

The gpio-matrix-keypad driver normally sets inactive columns as inputs
while scanning. This does not work for all hardware, which may require
the inactive columns to be actively driven in order to overcome any
pull-ups/downs on the columns.

Signed-off-by: David Rivshin <drivshin@allworx.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Documentation: devicetree: fix reference to legacy wakeup properties

This patch marks all the reference to the legacy wakeup bindings
and replaces them with the standard "wakeup-source" property.

All these legacy property are also listed under a separate section in
the generic wakeup-source binding document.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>

Input: matrix_keypad - change name of wakeup property to "wakeup-source"

Wakeup property of device is not Linux-specific, it describes intended
system behavior regardless of the OS being used. Therefore let's drop
"linux," prefix, and, while at it, use the same name as I2C bus does:
"wakeup-source".

We keep parsing old name to keep compatibility with old DTSes.

Cc: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: matrix-keypad - add device tree support

Also the driver was modifued to take advantage of recent improvements in
matrix_keypad_build_keymap() implementation, which automatically allocates
memory for keymap.

The driver was tested on AM335x EVM.

Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>