[source] layerscape: only support 64-bit for ls1088ardb/ls2088ardb

[LEDE Commits]

hauke pushed a commit to source.git, branch master:
https://git.lede-project.org/67c0c5978d5419c6dc5908c912ade316134c4f34

commit 67c0c5978d5419c6dc5908c912ade316134c4f34
Author: Yangbo Lu <yangbo.lu at nxp.com>
AuthorDate: Tue Oct 10 19:17:37 2017 +0800

    layerscape: only support 64-bit for ls1088ardb/ls2088ardb
    
    This is no requirement and plan to support 32-bit for ls1088ardb
    and ls2088ardb. Current 32-bit firmware for them couldn't work,
    so only keep 64-bit support for these two boards in menuconfig.
    
    Signed-off-by: Yangbo Lu <yangbo.lu at nxp.com>
---
 target/linux/layerscape/image/Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/target/linux/layerscape/image/Makefile b/target/linux/layerscape/image/Makefile
index 92206a3..5577b16 100644
--- a/target/linux/layerscape/image/Makefile
+++ b/target/linux/layerscape/image/Makefile
@@ -87,6 +87,7 @@ define Device/ls1012ardb
 endef
 TARGET_DEVICES += ls1012ardb
 
+ifeq ($(SUBTARGET),armv8_64b)
 define Device/ls1088ardb
   DEVICE_TITLE := ls1088ardb-$(SUBTARGET)
   DEVICE_PACKAGES += rcw-layerscape-ls1088ardb uboot-layerscape-$(SUBTARGET)-ls1088ardb mc-binary-ls1088ardb
@@ -106,5 +107,6 @@ define Device/ls2088ardb
 			append-rootfs | pad-rootfs | check-size 51380225
 endef
 TARGET_DEVICES += ls2088ardb
+endif
 
 $(eval $(call BuildImage))