[Why]
DMCUB will hang if we send a PSR unsupported set version command.
This can occur if we fall-through into the default case in the switch
statement for PSR version.
[How]
Add an unsupported check after the switch statement.
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Reviewed-by: Anthony Koo <Anthony.Koo@amd.com> Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com> Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>