drm/amd/display: change SMU repsonse timeout to 2s

[why]
driver has sent PMFW VBIOSSMC_MSG_SetDisplayIdleOptimizations while SMU
still processing a previous VBIOSSMC_MSG_SetHardMinDcfclkByFreq message.

[how]
same as RN, change the time out to2s.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Charlene Liu <Charlene.Liu@amd.com>
Reviewed-by: Chris Park <Chris.Park@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>