[ARM] pxa: remove unnecessary #include of pxa-regs.h and hardware.h

pxa-regs.h and hardware.h are not intended for use directly in driver
code, remove those unnecessary references.

Signed-off-by: Eric Miao <eric.miao@marvell.com>

sound/arm/pxa2xx-ac97-lib.c

@@ -21,7 +21,6 @@
 #include <sound/pxa2xx-lib.h>
 
 #include <asm/irq.h>
-#include <mach/hardware.h>
 #include <mach/regs-ac97.h>
 #include <mach/pxa2xx-gpio.h>
 #include <mach/audio.h>