realtek: Convert LGS310C to compressed kernel

There are too many supported Realtek devices so avoid activating the
rt loader recipe in the default builds. Just start with the LGS310C.

Signed-off-by: Markus Stockhausen <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/18397
Signed-off-by: Robert Marko <[email protected]>

target/linux/realtek/image/rtl838x.mk

@@ -194,6 +194,7 @@ endef
 TARGET_DEVICES += iodata_bsh-g24mb
 
 define Device/linksys_lgs310c
+  $(Device/uimage-rt-loader)
   SOC := rtl8380
   IMAGE_SIZE := 13504k
   DEVICE_VENDOR := Linksys