[ARM] 5391/1: AT91: Enable GPIO clocks earlier

Enable the GPIO clocks earlier in the initialization sequence.  This
allow the board-setup code to read and set GPIO pins.

Signed-off-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>