msm: clock: Check that round_rate is less than fmax

HW has maximum frequency requirements. Ensure that the clock frequency
returned from clk_round_rate() is within these limits.

Change-Id: I0d4ed5851fc1f9f76c0ad0622cc6609e64e5311f
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>