drm/amd/display: load iram for abm 2.3

[Why]
ABM 2.3 firmware expects information in iRAM that differs from previous
versions of ABM, so a mechanism is required to provide it with that
information.

[How]
Extend the existing iRAM definition to include parameters added by
ABM 2.3, and load it if DMCU is running ABM 2.3.

Signed-off-by: Josip Pavic <Josip.Pavic@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>