i2c: i2c-qcom-geni: Modify the bus vote for Core clocks

Set the driver's AB (Average bandwidth) vote to be at BCM level 0 based
on the design team's recommendation for I2C.
If there are concurrent I2C usescases on the same QUP instance the votes
will be added up as the driver votes on the same bus bandwidth end points.

Change-Id: Ia5aa1e042cff7f0851ee6be2258a3356247e9546
Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>