Patch from Richard Purdie

The Sharp SL-C7xx Series (Corgi) has 3 devices connected to the SSP
interface each needing different configurations of the port.
This code provides the necessary access and locking so drivers can
access these components. It uses the functions provided by the PXA
SSP driver to access the port.
It also adds some machine specific GPIO definitions used by this
code and adds some comments to existing definitions.

Signed-off-by: Richard Purdie
Signed-off-by: Russell King