manifest: tf-m: add support for RSA signatures with 2048-bit keys

Update TF-M reference to include a couple of commits which are
useful to properly size the stack & heap memory for Mbed TLS
in order to handle RSA signatures with 2048-bits (previously
only 1024-bits were possible).

Signed-off-by: Valerio Setti <[email protected]>

west.yml

@@ -341,7 +341,7 @@ manifest:
       groups:
         - tee
     - name: trusted-firmware-m
-      revision: bceac6cdfccb41ef4e289b9dca17daad48cda270
+      revision: fa020a8b001843bb5a115bc4692eaf6787e3d1de
       path: modules/tee/tf-m/trusted-firmware-m
       groups:
         - tee