populate_sdk_base: Fix aarch64 OLDEST_KERNEL sdk issues

aarch64 sets OLDEST_KERNEL to 3.14. This stops the aarch64 SDK installing on
anything with an older kernel which is clearly incorrect.

I attempted to extract the correct non-overridden version from the data store
but it proved problematic and I was running into data store issues. Those
are a separate problem but there isn't time to fix this right now.

Instead just code the SDK kernel version separately to work around this for
now (and fix the autobuilder tests and SDK usage).

(From OE-Core rev: 522ba4c51fff53566678b2689d0d63c393e417b3)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/populate_sdk_base.bbclass

@@ -81,6 +81,11 @@ python write_host_sdk_manifest () {
 POPULATE_SDK_POST_TARGET_COMMAND_append = " write_target_sdk_manifest ; "
 POPULATE_SDK_POST_HOST_COMMAND_append = " write_host_sdk_manifest; "
 
+# Some archs override this, we need the nativesdk version
+# turns out this is hard to get from the datastore due to TRANSLATED_TARGET_ARCH
+# manipulation.
+SDK_OLDEST_KERNEL = "2.6.32"
+
 fakeroot python do_populate_sdk() {
     from oe.sdk import populate_sdk
     from oe.manifest import create_manifest, Manifest
@@ -156,7 +161,7 @@ EOF
 	sed -i -e 's#@SDK_ARCH@#${SDK_ARCH}#g' \
 		-e 's#@SDKPATH@#${SDKPATH}#g' \
 		-e 's#@SDKEXTPATH@#${SDKEXTPATH}#g' \
-		-e 's#@OLDEST_KERNEL@#${OLDEST_KERNEL}#g' \
+		-e 's#@OLDEST_KERNEL@#${SDK_OLDEST_KERNEL}#g' \
 		-e 's#@REAL_MULTIMACH_TARGET_SYS@#${REAL_MULTIMACH_TARGET_SYS}#g' \
 		-e 's#@SDK_TITLE@#${SDK_TITLE}#g' \
 		-e 's#@SDK_VERSION@#${SDK_VERSION}#g' \