msm: clock-8974: Add support for the MMSSNOC_AHB RPM clock

Add an rpm clock that controls the MMSSNOC AHB clock source
and vote for the max SVS rate of 40 MHz on this clock in
post_init.

Change-Id: Iccb5f4bc336d8c96b3797628978ff7b4d2240a8b
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>