omap: annotate public functions

while read sym; do
	read f func line _ <<<$(cscope -d -L -1 $sym)
	if [ ! -z "$f" ]; then
		sed -i "${line}s/^/drm_public /" $f
	fi
done < /tmp/a.txt

In which /tmp/a.txt contains the public symbols from
omap-symbol-check. The idea here will be to switch the default
visibility to hidden so we don't export symbols we shouldn't.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Acked-by: Eric Engestrom <eric.engestrom@intel.com>