msm: clock: Use datatypes consistently to store clock rates

The clock API represents clock rates using unsigned longs,
whereas the clock drivers use an assortment of types (mostly
unsigned ints). Make consistent use of unsigned longs for rates.

Change-Id: I2e34d3d5db0ece40616d82274f60833aa70b7d5d
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>