drm/panel: clean up indentation issue

There is a continue statement that is indented one level too deeply,
remove the extraneous tab.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190925120357.10408-1-colin.king@canonical.com