video: msm_fb: Increase display timeout to 2 seconds

One second time out for no frame update, as in current implementation,
does not allow CABL to reach minimum backlight level possible because
histograms dont get generated after one second. So increase time out
period to two seconds which seem to be sufficient for complete black to
complete white and vice versa transitions.

CRs-fixed: 370804
Signed-off-by: Pravin Tamkhane <pravint@codeaurora.org>
Signed-off-by: Carl Vanderlip <carlv@codeaurora.org>
(cherry picked from commit 1bb4edf9242b0397975636a4442318713a53b5e6)

Change-Id: I298dbc94c32035bc7872341a028af979d74fe38f
Signed-off-by: Ramakrishna Prasad N <crpn@codeaurora.org>