ASoC: Intel: add sst shim register start-end variables

the shim registers start and end can be useful while parsing the shim addresses,
so add these

Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/intel/sst-dsp.h

@@ -53,6 +53,10 @@
 #define SST_CSR2		0x80
 #define SST_LTRC		0xE0
 #define SST_HDMC		0xE8
+
+#define SST_SHIM_BEGIN		SST_CSR
+#define SST_SHIM_END		SST_HDMC
+
 #define SST_DBGO		0xF0
 
 #define SST_SHIM_SIZE		0x100