[WHY] dc sw clock implementation of navi10 and raven are not exact the
same. dcccg, dchub reference clock initialization is done after dc calls
vbios dispcontroller_init table. for raven family, before
dispcontroller_init is called by dc, the ref clk values are referred
by sw clock implementation and program asic register using wrong
values. this causes dchub pstate error. This need provide valid ref
clk values. for navi10, since dispcontroller_init is not called,
dchubbub_global_timer_enable = 0, hubbub2_get_dchub_ref_freq will
hit aeert. this need remove hubbub2_get_dchub_ref_freq from this
location and move to dcn20_init_hw.

[HOW] for all asic, initialize dccg, dchub ref clk with data from
vbios firmware table by default. for raven asic family, use these data
from vbios, for asic which support sw dccg component, like navi10,
read ref clk by sw dccg functions and update the ref clk.
Signed-off-by: hersen wu <hersenxs.wu@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>