msm: mdss: shutoff axi memory and periphery when axi clk is off

Because of CBCR update, mdss driver needs to control mdss axi clock
state of memory core and periphery control when branch clock is off.
Since mdss does not have retention requirement for axi, both memory core
and periphery control can be turned off to conserve power when mdss
axi clock is off.

CRs-Fixed: 1044375
Change-Id: Ia609549304be97cdaeff0f30ff0ca8ad5e22af75
Signed-off-by: Alan Kwong <akwong@codeaurora.org>