drm/amd/powerplay: Set higher SCLK&MCLK frequency than dpm7 in OD (v2)

Fix the issue that SCLK&MCLK can't be set higher than dpm7 when
OD is enabled in SMU7.

v2: fix warning (Alex)

Signed-off-by: Kenneth Feng <kenneth.feng@amd.com>
Acked-by: Rex <Zhu&lt;rezhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>