oeqa/oetest: Fix compatibility SDK tests using eSDK.
When run SDK tests over eSDK we need to use SDKExtTestContext
instead of SDKTestContext because if we use SDKTestContext search
for SDK manifest and depends on the SDK manifest generation so
populate_sdk needs to be executed.
Adds a compatibility mode flag to SDKExtTestContext for search tests
over sdk module instead of sdkext module and change testsdk calls
to comply with this new param.
Signed-off-by: Aníbal Limón <anibal.limon@linux.intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
