drm/vc4: dsi: Register dsi0 as the correct vc4 encoder type

vc4_dsi was registering both dsi0 and dsi1 as VC4_ENCODER_TYPE_DSI1
which seemed to work OK for a single DSI display, but fails
if there are two DSI displays connected.

Update to register the correct type.

Fixes: 4078f575 ("drm/vc4: Add DSI driver")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-15-maxime@cerno.tech


Signed-off-by: Maxime Ripard <maxime@cerno.tech>