drm/bridge: cdns-mhdp8546: Remove a redundant check on existence of bridge->encoder

drm/bridge: cdns-mhdp8546: Remove a redundant check on existence of bridge->encoder

In the cdns_mhdp_connector_init() function, the check on the existence
of bridge->encoder is not necessary, as it has already been checked in
the drm_bridge_attach() function. As the cdns_mhdp_connector_init() is
only called by cdns_mhdp_attach(), it is guaranteed that the .encoder
member of the struct drm_bridge is not NULL when cdns_mhdp_attach() gets
called.

Remove the redundant checking codes "if (!bridge->encoder) { ... }".

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sui Jingfeng <sui.jingfeng@linux.dev>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240513153109.46786-8-sui.jingfeng@linux.dev