drm/msm/dp: fix missing #include

Some randconfig builds fail when drm/drm_bridge.h is not included
implicitly in this file:

drivers/gpu/drm/msm/dp/dp_parser.c:279:25: error: implicit declaration of function 'devm_drm_panel_bridge_add' [-Werror,-Wimplicit-function-declaration]
        parser->panel_bridge = devm_drm_panel_bridge_add(dev, panel);

Fixes: 4b296d15

 ("drm/msm/dp: Allow attaching a drm_panel")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20211026083254.3396322-1-arnd@kernel.org
Signed-off-by: Rob Clark <robdclark@chromium.org>