[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>
diff --git a/sound/arm/pxa2xx-pcm-lib.c b/sound/arm/pxa2xx-pcm-lib.c
index 75a0d74..108b6432 100644
--- a/sound/arm/pxa2xx-pcm-lib.c
+++ b/sound/arm/pxa2xx-pcm-lib.c
@@ -12,8 +12,7 @@
 #include <sound/pcm_params.h>
 #include <sound/pxa2xx-lib.h>
 
-#include <asm/dma.h>
-#include <mach/pxa-regs.h>
+#include <mach/dma.h>
 
 #include "pxa2xx-pcm.h"