drm/rcar-du: dsi: Fix PHY lock bit check

The driver checks for bit 16 (using CLOCKSET1_LOCK define) in CLOCKSET1
register when waiting for the PPI clock. However, the right bit to check
is bit 17 (CLOCKSET1_LOCK_PHY define). Not only that, but there's
nothing in the documents for bit 16 for V3U nor V4H.

So, fix the check to use bit 17, and drop the define for bit 16.

Fixes: 15535831 ("drm: rcar-du: Add R-Car DSI driver")
Fixes: 11696c5e ("drm: Place Renesas drivers in a separate dir")
Cc: stable@vger.kernel.org
Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241217-rcar-gh-dsi-v5-1-e77421093c05@ideasonboard.com