Revert "adv7481: return error when PLL lock fails"

This reverts commit 44d8abb6.

If we return error on PLL lock failure, it results in open_stream
failure for TIF. So, if we open the TV app first and then connect
HDMI cable, it will not start streaming. Therefore reverting this
change.

Change-Id: Ic99a6986a3138bc3abb9e65eb598a743f1634c5c
Signed-off-by: Suprith Malligere Shankaregowda <supgow@codeaurora.org>