manifest: Add PSA ed25519 image encryption/verification to MCUboot

Update MCUboot version to birng in PSA encryption support.

Signed-off-by: Dominik Ermel <dominik.ermel@nordicsemi.no>

west.yml

@@ -131,7 +131,7 @@ manifest:
           compare-by-default: true
     - name: mcuboot
       repo-path: sdk-mcuboot
-      revision: v2.1.0-ncs1
+      revision: pull/323/head
       path: bootloader/mcuboot
     - name: qcbor
       url: https://github.com/laurencelundblade/QCBOR