clk: msm: Add support for CPU clocks for MDM9x07/55

Clock A7 is the CPU clock driver to support CPU scaling on MDM9x07 and
MDM9x55, add support for the same.

Change-Id: I4b598db66269f513db619a858b151205851c33d4
Signed-off-by: Taniya Das <tdas@codeaurora.org>