drm/amd/display: Enable Seamless Boot Transition for Multiple Streams

[why]
dc previously had bugs that interfered with the ability to inherit a
timing from a device with multiple streams (without flash/blanking).
After this fix there is still a dependency on UEFI support.

[how]
fixed 3 bugs: loaded MPC state, changed bw_optimize flag to a counter
instead of a boolean, and reading dpp/disp clk from HW to ensure we
don't raise the clock's when we're not supposed to.

Signed-off-by: Martin Leung <martin.leung@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>