[ARM] Fix warning in arch/arm/mach-pxa/generic.c

Fix
 arch/arm/mach-pxa/generic.c:242: warning: 'struct i2c_pxa_platform_data' declared inside parameter list
caused by missing asm/arch/i2c.h include.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-pxa/generic.c

@@ -34,6 +34,7 @@
 #include <asm/arch/udc.h>
 #include <asm/arch/pxafb.h>
 #include <asm/arch/mmc.h>
+#include <asm/arch/i2c.h>
 
 #include "generic.h"