ARM: pxa: fix including linux/gpio.h twice

arch/arm/mach-pxa/pxa27x.c included 'linux/gpio.h' twice, remove
the duplicate.
Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>

arch/arm/mach-pxa/pxa27x.c

@@ -22,7 +22,6 @@
 #include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/i2c/pxa-i2c.h>
-#include <linux/gpio.h>
 
 #include <asm/mach/map.h>
 #include <mach/hardware.h>