msm: msm_bus: Use appropriate data type

In function bimc_div(), an int64 variable is compared with
uint32 type, which leads to the below warning:
	warning: comparison of distinct pointer types lacks a cast
Use appropriate data type to avoid such warning.

Change-Id: I79f9f39c34b333f20eb55879116e25e507e6c145
Signed-off-by: Sudarshan Rajagopalan <sudaraja@codeaurora.org>