[ARM] 5243/1: ep93xx: bugfix, GPIO ports C and F are swapped

In the GPIOLIB support for EP93xx ports C anf F are swapped. This
patch correct it.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>