adv7481: Add support for CVBS interrupts

Add signal lock/unlock interrupts for CVBS input. This
enables to detect when input stream is stop/start due
to reasons such as cable plug out/plugin. Also update
driver code with the new macro added with this patch
and clean up header to move tab to space for consistent
editing/viewing across editors.

CRs-Fixed: 1033059
Change-Id: I8d28182de6f36c1301a2a04abd602cfbe5516be8
Signed-off-by: Shiju Mathew <shijum@codeaurora.org>