drm/amd/display: Correct FIXED_VS Link Rate Toggle Condition

[WHY&HOW]
The condition is only perform toggle if FIXED_VS LTTPR reports
no IEEE OUI.
The literal "\x0,\x0,\x0" contains commas changes the
bytes being compared to {0x00,0x2C,0X00}.
The correct literal should be "\x00\x00\x00" without commas.

Reviewed-by: Charlene Liu <charlene.liu@amd.com>
Reviewed-by: Wenjing Liu <wenjing.liu@amd.com>
Signed-off-by: Jing Zhou <Jing.Zhou@amd.com>
Signed-off-by: Roman Li <roman.li@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>