iMX51: introduce IMX_GPIO_NR

Currently, to define a GPIO number, we're using something like :

#define EFIKAMX_PCBID0         (2*32 + 16)

to define GPIO 3 16.

This is not really readable and it's error prone imho (note the 3 vs 2).
So, I'm introducing a new macro to define this in a better way. Now, the
code sample become :

#define EFIKAMX_PCBID0         IMX_GPIO_NR(3, 16)

v2:
- move to gpio.h
- add parens & spaces
- switch to IMX_GPIO_NR instead of MX51_GPIO_NR

Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Cc: Amit Kucheria <amit.kucheria@linaro.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Eric Bénard <eric@eukrea.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/mach-mx5/eukrea_mbimxsd-baseboard.c b/arch/arm/mach-mx5/eukrea_mbimxsd-baseboard.c
index 2751b11..c6c2320 100644
--- a/arch/arm/mach-mx5/eukrea_mbimxsd-baseboard.c
+++ b/arch/arm/mach-mx5/eukrea_mbimxsd-baseboard.c
@@ -70,8 +70,8 @@
 	MX51_PAD_SD1_DATA3__SD1_DATA3,
 };
 
-#define GPIO_LED1	(2 * 32 + 30)
-#define GPIO_SWITCH1	(2 * 32 + 31)
+#define GPIO_LED1	IMX_GPIO_NR(3, 30)
+#define GPIO_SWITCH1	IMX_GPIO_NR(3, 31)
 
 static struct gpio_led eukrea_mbimxsd_leds[] = {
 	{