ipq806x: disable ea8500 image by default

Linksys EA8500 is currently broken after the kernel 5.15 bump. Disable
compiling it by default from buildbot to prevent brick from the user.

Don't mark it as BROKEN to permit user to compile images and permit devs
to bisect the problem with the users.

The current problem with the device is that the switch is not detected
and we can't comunicate with it via MDIO.

Signed-off-by: Christian Marangi <[email protected]>

target/linux/ipq806x/image/generic.mk

@@ -163,6 +163,7 @@ define Device/linksys_ea7500-v1
 	IMAGE/factory.bin := append-kernel | pad-to $$$$(KERNEL_SIZE) | \
 		append-ubi | pad-to $$$$(PAGESIZE)
 	DEVICE_PACKAGES := ath10k-firmware-qca99x0-ct
+	DEFAULT := n
 endef
 TARGET_DEVICES += linksys_ea7500-v1