ARM: 7240/1: Make ARCH_NR_GPIO a Kconfig variable

Change ARCH_NR_GPIO into a Kconfig variable as suggested by Russel King.
This makes ARCH_NR_GPIO single zImage friendly. The default value for
tegra is defined as well.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/include/asm/gpio.h b/arch/arm/include/asm/gpio.h
index 11ad0bf..7151753b 100644
--- a/arch/arm/include/asm/gpio.h
+++ b/arch/arm/include/asm/gpio.h
@@ -1,6 +1,10 @@
 #ifndef _ARCH_ARM_GPIO_H
 #define _ARCH_ARM_GPIO_H
 
+#if CONFIG_ARCH_NR_GPIO > 0
+#define ARCH_NR_GPIO CONFIG_ARCH_NR_GPIO
+#endif
+
 /* not all ARM platforms necessarily support this API ... */
 #include <mach/gpio.h>