msm: mdss: reset intf_stopped flag for sctl when exiting LP states

When exiting low power state (LP1 of LP2), ensure that the intf_stopped
flag is reset for the secondary ctl as well, otherwise it may result in
the display corruption for that ctl path.

Change-Id: I2ac9cff00e25a3cae6999e33c9f5a7a959413277
Signed-off-by: Veera Sundaram Sankaran <veeras@codeaurora.org>