pm: Recalculate I2C clock on engine clock setting.
On pre-R6xx the DDC clock is derived from the engine clock, thus changing the
engine clock implies that the DDC clock is to be updated as well.
Same should be done for radeon KMS.
It's already done for kms. If we use the hw engines we take the pm mutex and call get_engine_clock() to get the current sclk.
Oh, OK, thanks.
Browsing ooold e-mails I noticed last time we didn't implement that. I thought it was forgotten.