[ARM] 5242/1: ep93xx: bugfix, GPIO port F enable register offset

The GPIO port F enable register offset points to the wrong register,
0x5c is the IntStsF register. The correct offset is 0x58. This patch
corrects it.

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