coresight-tpdm: add fix for MSR erratum

Some TPDMs require to program MSR registers after enabling the DSB
subunit.
This change adds support for such TPDMs.

Change-Id: Iff5c1d73f752c8f9ff483e37cf65f9fe8e2901ca
Signed-off-by: Shashank Mittal <mittals@codeaurora.org>