msm: msm_bus: Add support for QoS clk for fabrics

Some bus masters require an additional QoS clock to be enabled in addition
to the bus clock itself when changing their QoS mode to limiter or
regulator. This clock is enabled once and disabled when voting to turn off
the bus clock itself.

Change-Id: I485567b1e1f584ea711c130d3dd0eea3eca49355
Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>
Signed-off-by: Alok Chauhan <alokc@codeaurora.org>