clk: msm: clock-cpu: Fix overflow in CCI clock rate for 32 bit

The CCI rate is incorrectly calculated due to an overflow, thus fix the
same for 32 bit compilers, which was causing cci clock set failures on 32
bit systems.

CRs-Fixed: 971371
Change-Id: I87da3260c7cf7ce789b6920a75ad20ebabbfc092
Signed-off-by: Taniya Das <tdas@codeaurora.org>