fix(mte): improve ENABLE_FEAT_MTE deprecation warning

ENABLE_FEAT_MTE was deprecated in commit c282384dbb45 ("refactor(mte):
remove mte, mte_perm"), but the check in the build system is only
covering the "ENABLE_FEAT_MTE=1" case.
Fix the check to cover every mentioning of ENABLE_FEAT_MTE.

Change-Id: Ia663f50016455f93ecfdac8aeaba34d9059600ea
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
1 file changed