clk: msm: clock-generic: Fix max_div calculation for 32 bit

The ULONG_MAX value on 32 bit compilers is +4,294,967,295 and when divided
with some high frequencies, it could lead to min_div > max_div. Thus
resulting in clk_set_rate failure for higher frequencies.

CRs-Fixed: 971371
Change-Id: Id982328aeadf24d29e295e042a57453ea4e35c1b
Signed-off-by: Taniya Das <tdas@codeaurora.org>