drm/bridge: imx8qxp-pixel-link: simplify logic to find next bridge

drm/bridge: imx8qxp-pixel-link: simplify logic to find next bridge

imx8qxp_pixel_link_find_next_bridge() uses a sophisticated logic to find
the preferred next bridge, using an array with two supporting index
variables. This is more sophisticated than required because we only ever
need a pointer to the "current" bridge and to the "best so far" bridge.

Additionally this logic is going to make the addition of proper refcounting
quite complex.

Rewrite the logic using two drm_bridge pointers, which is by itself
slightly simpler and is a preparation step for introducing bridge
refcounting in a later commit.

Also reword a comment to make it clearer.

Reviewed-by: Liu Ying <victor.liu@nxp.com>
Link: https://patch.msgid.link/20260107-drm-bridge-alloc-getput-drm_of_find_bridge-v4-1-a62b4399a6bf@bootlin.com
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>