drm/amd/display : Log DP link training downspread info

Update the existing log with DP LT downspread info:

[Downstream devices shall support down spreading of the link clock.
The down-spread amplitude shall either be disabled (0.0%) or up to 0.5%,
as written by the upstream device to the DOWNSPREAD_CTRL register
(DPCD 00107h). The modulation frequency range shall be 30 to 33 kHz]

Besides, fix checkpatch warning:

CHECK: Alignment should match open parenthesis

Cc: Mario Limonciello <mario.limonciello@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Leo Li <sunpeng.li@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>