arm/dt: apq: 8084: Remove control of mem iface clock in graphics

The msm_iface_clk is supposed to be controlled by rpm. Remove this
clock from being controlled at the kernel driver level.

Change-Id: I41770c38208aec7f0d31b669d817991115929ce0
Signed-off-by: Shubhraprakash Das <sadas@codeaurora.org>