drm/radeon: lower the ref * post PLL maximum once more

Let's be conservative and use 100 here until we find something better.

Bugs: https://bugzilla.kernel.org/show_bug.cgi?id=75241

Signed-off-by: Christian König <christian.koenig@amd.com>

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