Fixes stability issues.

v2: clamp sclk to 600 Mhz

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=103370Acked-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org