ARM: dts: msm: Change MNOC AHB to set rate only for msm8996

Modify the MMNOC AHB bus clock to be set rate only, meaning bus driver
will only set a rate on the clock. The clients will enable their
respective branch clocks.

Change-Id: I4fd288ff8448239b31dea97f79cda673a3c42799
Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>