drm/radeon/dpm: adjust the vblank time checks for eg, ni, si

According to the internal teams, we never hit the limit for
mclk switching on these asics, so we can disable the check.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --cc drivers/gpu/drm/radeon/cypress_dpm.c
Simple merge

diff --cc drivers/gpu/drm/radeon/ni_dpm.c
Simple merge