linux-firmware: add firmware for RTL8723BS SDIO modules

Adds firmware package for Realtek RTL8723BS SDIO Wireless LAN NIC driver
available in the staging.

Signed-off-by: Petr Štetiar <ynezz@true.cz>

package/firmware/linux-firmware/realtek.mk

@@ -79,6 +79,13 @@ define Package/rtl8723bu-firmware/install
 endef
 $(eval $(call BuildPackage,rtl8723bu-firmware))
 
+Package/rtl8723bs-firmware = $(call Package/firmware-default,RealTek RTL8723BS firmware)
+define Package/rtl8723bs-firmware/install
+	$(INSTALL_DIR) $(1)/lib/firmware/rtlwifi
+	$(INSTALL_DATA) $(PKG_BUILD_DIR)/rtlwifi/rtl8723bs*.bin $(1)/lib/firmware/rtlwifi
+endef
+$(eval $(call BuildPackage,rtl8723bs-firmware))
+
 Package/rtl8821ae-firmware = $(call Package/firmware-default,RealTek RTL8821AE firmware)
 define Package/rtl8821ae-firmware/install
 	$(INSTALL_DIR) $(1)/lib/firmware/rtlwifi