ARM: PXA: fix includes in pxa2xx_cm_x2xx PCMCIA driver

The includes in the pxa2xx_cm_x2xx PCMCIA driver are rather random;
the driver doesn't require anything from these headers except the
cpu_is_xxx() macros which come from another include.

The concern is that it's getting these definitions via mach/system.h,
which is supposed to only be included by arch/arm/kernel/process.c.
As this header is scheduled for cleanup (and elimination) keeping
the status quo will cause build errors.  So lets fix properly and
independent of the future work.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

drivers/pcmcia/pxa2xx_cm_x2xx.c

@@ -12,9 +12,8 @@
 
 #include <linux/module.h>
 
-#include <asm/system.h>
 #include <asm/mach-types.h>
-#include <mach/system.h>
+#include <mach/hardware.h>
 
 int cmx255_pcmcia_init(void);
 int cmx270_pcmcia_init(void);