[ARM] pxa: move GPIO register definitions into <mach/gpio.h>

This makes gpio.c fully independent of pxa-regs.h (except for the
virtual address of the registers).

Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: Eric Miao <eric.miao@marvell.com>
diff --git a/arch/arm/mach-pxa/mainstone.c b/arch/arm/mach-pxa/mainstone.c
index 673f838..a6c8429 100644
--- a/arch/arm/mach-pxa/mainstone.c
+++ b/arch/arm/mach-pxa/mainstone.c
@@ -42,6 +42,7 @@
 #include <asm/mach/flash.h>
 
 #include <mach/pxa27x.h>
+#include <mach/gpio.h>
 #include <mach/mainstone.h>
 #include <mach/audio.h>
 #include <mach/pxafb.h>