uio: uio_fsl_elbc_gpcm: new driver

This driver provides UIO access to memory of a peripheral connected
to the Freescale enhanced local bus controller (eLBC) interface
using the general purpose chip-select mode (GPCM).

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>