[ARM] 5079/1: Warn people when using pxa2xx-gpio.h

Warn people when using pxa2xx-gpio.h as it is only here for backwards
compatibility. The new mfp-pxa2[57]x.h and the relevant API should be used
instead.
Signed-off-by: NStefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

include/asm-arm/arch-pxa/pxa2xx-gpio.h

 #ifndef __ASM_ARCH_PXA2XX_GPIO_H
 #define __ASM_ARCH_PXA2XX_GPIO_H
 
+#warning Please use mfp-pxa2[57]x.h instead of pxa2xx-gpio.h
+
 /* GPIO alternate function assignments */
 
 #define GPIO1_RST		1	/* reset */