modules: hal_silabs: Set multiprotocol define expected by bt stack

Set `SL_RAIL_LIB_MULTIPROTOCOL_SUPPORT` to `1` when Rail
Multiprotocol Kconfig is enabled.

This is required to run the Bluetooth multiprotocol initialization
code during `sl_btctrl_init`.

Signed-off-by: James Smith <[email protected]>

Author: loopj

modules/hal_silabs/simplicity_sdk/config/ll/sl_btctrl_config.h

@@ -123,6 +123,10 @@
 #define SL_BLUETOOTH_NO_VS_HCI_COMMANDS
 #endif
 
+#ifdef CONFIG_SILABS_SISDK_RAIL_MULTIPROTOCOL
+#define SL_RAIL_LIB_MULTIPROTOCOL_SUPPORT 1
+#endif
+
 #define SL_CATALOG_BLUETOOTH_RCP_PRESENT
 
 /* The following features are not currently supported with Zephyr */
@@ -138,7 +142,6 @@
 #undef SL_CATALOG_BLUETOOTH_FEATURE_USER_POWER_CONTROL_PRESENT
 #undef SL_CATALOG_KERNEL_PRESENT /* Only relevant in the SiSDK RTOS adaptation */
 #undef SL_CATALOG_RAIL_UTIL_COEX_PRESENT
-#undef SL_RAIL_LIB_MULTIPROTOCOL_SUPPORT
 
 /* Maps the controller configuration options from Kconfig to Silabs defines */
 #define SL_BT_CONTROLLER_BUFFER_MEMORY      CONFIG_BT_SILABS_EFR32_BUFFER_MEMORY