OMAP: DSP: Fix DSP build for omap1

OMAP2430 builds/boots ok for me, but as Khem just pointed out,
OMAP1 builds are broken.

This patch gets OMAP1 building again:
Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/plat-omap/dsp/dsp_common.h

@@ -28,10 +28,12 @@
 #include <asm/arch/mmu.h>
 #include "hardware_dsp.h"
 
+#ifdef CONFIG_ARCH_OMAP2
 #include "../../mach-omap2/prm.h"
 #include "../../mach-omap2/prm_regbits_24xx.h"
 #include "../../mach-omap2/cm.h"
 #include "../../mach-omap2/cm_regbits_24xx.h"
+#endif
 
 #define DSPSPACE_SIZE	0x1000000