enc-amf: Update plugin to Version 2.5.1

Fixes the Profile Level problem with integrated AMD Vega GPUs.

(Jim: Also fixes an issue where the amf-test executable would not build)

Closes obsproject/obs-studio#1619

plugins/enc-amf

@@ -1 +1 @@
-Subproject commit 72d566ec282a53a2194390813a53c86d77d94aa1
+Subproject commit 221063025aa245ecaa157df746596b3a73a8af8b