Updated SDK target picking

src/system/BUILD.gn

@@ -44,7 +44,9 @@ declare_args() {
   # see https://clang.llvm.org/docs/ThreadSafetyAnalysis.html
   chip_enable_thread_safety_checks = is_clang
 
-  chip_external_sdk_target = ""
+  # SDK target for the platform
+  # If left blank the SDK target will be determined by the device platform
+  chip_platform_sdk_target = ""
 }
 
 if (chip_project_config_include_dirs == [] &&
@@ -53,6 +55,42 @@ if (chip_project_config_include_dirs == [] &&
   chip_project_config_include_dirs += [ "${chip_root}/config/standalone" ]
 }
 
+if(chip_platform_sdk_target == "")
+{
+  if (target_cpu != "esp32") {
+    if (chip_system_config_use_lwip) {
+      chip_platform_sdk_target = "${lwip_root}:lwip"
+    } else {
+      if (chip_device_platform == "efr32") {
+        chip_platform_sdk_target = "${efr32_sdk_build_root}:efr32_sdk"
+      }
+      if (chip_device_platform == "qpg") {
+        chip_platform_sdk_target = "${qpg_sdk_build_root}:qpg_sdk"
+      }
+      if (chip_device_platform == "nxp") {
+        chip_platform_sdk_target = "${nxp_sdk_build_root}:nxp_sdk"
+      }
+      if (chip_device_platform == "cyw30739") {
+        chip_platform_sdk_target = "${cyw30739_sdk_build_root}:cyw30739_sdk"
+      }
+      if (chip_device_platform == "stm32") {
+        chip_platform_sdk_target = "${stm32_sdk_build_root}:stm32_sdk"
+      }
+      if (chip_device_platform == "bl702") {
+        chip_platform_sdk_target = "${bouffalolab_iot_sdk_build_root}/bl702:bl_iot_sdk"
+      }
+      if (chip_device_platform == "bl702l") {
+        chip_platform_sdk_target = "${bouffalolab_iot_sdk_build_root}/bl702l:bl_iot_sdk"
+      }
+      if (chip_device_platform == "mt793x") {
+        chip_platform_sdk_target = "${mt793x_sdk_build_root}:mt793x_sdk"
+      }
+
+      # Add platform here as needed.
+    }
+  }
+}
+
 if (chip_device_platform == "cc13x4_26x4") {
   import("//build_overrides/ti_simplelink_sdk.gni")
 } else if (chip_device_platform == "efr32") {
@@ -174,41 +212,8 @@ source_set("system_config_header") {
 
   public_deps = []
 
-  if (target_cpu != "esp32") {
-    if (chip_system_config_use_lwip) {
-      public_deps += [ "${lwip_root}:lwip" ]
-    } else {
-      if (chip_device_platform == "efr32") {
-        public_deps += [ "${efr32_sdk_build_root}:efr32_sdk" ]
-      }
-      if (chip_device_platform == "qpg") {
-        public_deps += [ "${qpg_sdk_build_root}:qpg_sdk" ]
-      }
-      if (chip_device_platform == "nxp") {
-        public_deps += [ "${nxp_sdk_build_root}:nxp_sdk" ]
-      }
-      if (chip_device_platform == "cyw30739") {
-        public_deps += [ "${cyw30739_sdk_build_root}:cyw30739_sdk" ]
-      }
-      if (chip_device_platform == "stm32") {
-        public_deps += [ "${stm32_sdk_build_root}:stm32_sdk" ]
-      }
-      if (chip_device_platform == "bl702") {
-        public_deps += [ "${bouffalolab_iot_sdk_build_root}/bl702:bl_iot_sdk" ]
-      }
-      if (chip_device_platform == "bl702l") {
-        public_deps += [ "${bouffalolab_iot_sdk_build_root}/bl702l:bl_iot_sdk" ]
-      }
-      if (chip_external_sdk_target != "") {
-        public_deps += [ "${chip_external_sdk_target}" ]
-      }
-
-      # Add platform here as needed.
-    }
-  }
-
-  if (chip_device_platform == "mt793x") {
-    public_deps += [ "${mt793x_sdk_build_root}:mt793x_sdk" ]
+  if(chip_platform_sdk_target != "") {
+    public_deps += [ chip_platform_sdk_target ]
   }
 }