drm/bridge: Rename bridge helpers targeting a bridge chain

drm/bridge: Rename bridge helpers targeting a bridge chain

[ Upstream commit 0aaba9a2d6995e53ece4125a956ab49de07e53c6 ]

Change the prefix of bridge helpers targeting a bridge chain from
drm_bridge_ to drm_bridge_chain_ to better reflect the fact that
the operation will happen on all elements of chain, starting at the
bridge passed in argument.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191203141515.3597631-2-boris.brezillon@collabora.com
Stable-dep-of: 13fcfcb2a9a4 ("drm/msm/mdp5: Add check for kzalloc")
Signed-off-by: Sasha Levin <sashal@kernel.org>