simplicity_sdk: add MGM24 support

Signed-off-by: Tamas Jozsi <[email protected]>

Author: silabs-bozont

scripts/import_simplicity_sdk.py

@@ -29,6 +29,8 @@
   "platform/Device/SiliconLabs/EFR32MG2[149]/Source/system_*.c",
   "platform/Device/SiliconLabs/EFR32ZG2[3]/Include/*.h",
   "platform/Device/SiliconLabs/EFR32ZG2[3]/Source/system_*.c",
+  "platform/Device/SiliconLabs/MGM24/Include/*.h",
+  "platform/Device/SiliconLabs/MGM24/Source/system_*.c",
   "platform/driver/gpio/inc/*.h",
   "platform/driver/gpio/src/*.c",
   "platform/driver/i2c/inc/*.h",