qcacmn: Define shadow register as 0 in else case

Define shadow register value as 0 in else case where none
of the chips supporting SHADOW configuration are enabled. This
is needed for low memory configuration profiles where
QCN9000 and QCA6290 are undefined.

Change-Id: I6281568e830b506707aeb96d3ea03811cc1de8a7

hal/wifi3.0/hal_api.h

@@ -39,6 +39,8 @@
 #define SHADOW_REGISTER_END_ADDRESS_OFFSET \
 	((SHADOW_REGISTER_START_ADDRESS_OFFSET) + (4 * (MAX_SHADOW_REGISTERS)))
 #define SHADOW_REGISTER(x) ((SHADOW_REGISTER_START_ADDRESS_OFFSET) + (4 * (x)))
+#else
+#define SHADOW_REGISTER(x) 0
 #endif /* QCA_WIFI_QCA6390 || QCA_WIFI_QCA6490 || QCA_WIFI_QCA6750 */
 
 #define MAX_UNWINDOWED_ADDRESS 0x80000