msm: mdss: reset intf number from control path
msm: mdss: reset intf number from control path

Interface number is not properly reset when control path is changed
between writeback and interface. This gives incorrect information in
debug statistics.

Change-Id: I7816548791a9ed6058cbf0b3fd5484ed025c74f6
Signed-off-by: Adrian Salido-Moreno <f4561ccbe90a02dadc9d168b29bfea0c1b57222c@codeaurora.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas