[ARM] 4506/1: HP Jornada 7XX: Addition of SSP Platform Driver

These patches add full SSP/MCU support for the HP Jornada 720
machine.  Its needed to handle keyboard, touchscreen, battery
and backlight/lcd.

The main driver exports functions and the header file exports
the command values. When talking to the MCU the general procedure
is to start MCU, send command (using ssp_inout(command)), the
proper reply is always TXDUMMY.  After receiving TXDUMMY you can
send the value you wish pushed (for example brightness level).
End with ssp_end() so the spinlock gets unlocked.

Drivers using this havent been implemented yet, but will shortly.

Signed-off-by: Kristoffer Ericson <Kristoffer.ericson@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>