Bluetooth: hci_h5: btrtl: Add support for RTL8821CS

RTL8821CS is a WiFi + Bluetooth combo chip from Realtek that provides
WiFi A/B/G/N/AC over an SDIO interface and Bluetooth 4.2 over a UART
interface.

Note that the firmware this was tested with was firmware version
0x75b8f098.

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

drivers/bluetooth/btrtl.c

@@ -128,6 +128,14 @@ static const struct id_table ic_id_table[] = {
 	  .fw_name  = "rtl_bt/rtl8821c_fw.bin",
 	  .cfg_name = "rtl_bt/rtl8821c_config" },
 
+	/* 8821CS */
+	{ IC_INFO(RTL_ROM_LMP_8821A, 0xc, 0x8, HCI_UART),
+	  .config_needed = true,
+	  .has_rom_version = true,
+	  .has_msft_ext = true,
+	  .fw_name  = "rtl_bt/rtl8821cs_fw.bin",
+	  .cfg_name = "rtl_bt/rtl8821cs_config" },
+
 	/* 8761A */
 	{ IC_INFO(RTL_ROM_LMP_8761A, 0xa, 0x6, HCI_USB),
 	  .config_needed = false,