drtm: rename DRTM build config

Since the DRTM implementation currently doesn’t use any TPM, it’s
best to avoid mentioning it in the TF fragment and the
corresponding build configuration. Hence renamed these files by just
mentioning the HASH algorithm with which images are measured and
recorded in the Event Log.

Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: I05604f72361c554cdea4618b0ec2b0eb6ecdd5ce
2 files changed