gemini: fix parallel build

Due to the missing PROFILES all images are build, regardless of the
selected (or currently processed in case of a multi profile build).

Because of the race condition builds with eight parallel jobs fail,
which can be seen on the build bots as well.

Add the PROFILES variable for now, till the root cause is identified.

Signed-off-by: Mathias Kresin <dev@kresin.me>

target/linux/gemini/image/Makefile

@@ -71,6 +71,7 @@ endef
 
 # All DTB files are prefixed with "gemini-"
 define Device/Default
+	PROFILES := Default
 	DEVICE_DTS := $(patsubst %.dtb,%,$(notdir $(wildcard $(if $(IB),$(KDIR),$(DTS_DIR))/*-$(1).dtb)))
 	KERNEL_DEPENDS = $$(wildcard $(DTS_DIR)/$$(DEVICE_DTS).dts)
 	KERNEL_NAME := zImage