drm/radeon/dpm: fix r600_enable_sclk_control()
drm/radeon/dpm: fix r600_enable_sclk_control()

Actually program the correct register to enable
engine clock scaling control.

Signed-off-by: Alex Deucher <08dc22c6156113f2deff178e35e3ed9b24d6af9e@amd.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs