[ARM] w90x900: fix build errors and warnings

Fix:
arch/arm/mach-w90x900/mach-w90p910evb.c:65: error: 'W90X900_PA_UART' undeclared here (not in a function)

and silence warnings caused by inappropriate inclusion of mach/system.h.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-w90x900/mach-w90p910evb.c

@@ -29,6 +29,7 @@
 #include <asm/mach-types.h>
 
 #include <mach/regs-serial.h>
+#include <mach/map.h>
 
 #include "cpu.h"
 

arch/arm/mach-w90x900/time.c

@@ -28,7 +28,6 @@
 #include <asm/mach/irq.h>
 #include <asm/mach/time.h>
 
-#include <mach/system.h>
 #include <mach/map.h>
 #include <mach/regs-timer.h>