drm/amd/display: Move some init routines to dm_sw_init()

drm/amd/display: Move some init routines to dm_sw_init()

Move creation of CGS device node and the DAL allocation list from
amdgpu_dm_init() to dm_sw_init() which runs before dmub's sw init hook.

This is required for communicating with the VBIOS DMUB image from the
VBIOS that was loaded for early pre-os boot.

Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>