Update tf-psa-crypto pointer

Signed-off-by: Felix Conway <felix.conway@arm.com>
diff --git a/tf-psa-crypto b/tf-psa-crypto
index 4a9f29b..f936d86 160000
--- a/tf-psa-crypto
+++ b/tf-psa-crypto
@@ -1 +1 @@
-Subproject commit 4a9f29b05c661bd874c75d80339fcce00adea4e0
+Subproject commit f936d86b2587eb4a961cac5b3b95b949ee056ee6