drm/panel: raydium-rm67200: Move initialization from enable() to prepare stage

drm/panel: raydium-rm67200: Move initialization from enable() to prepare stage

[ Upstream commit 691674a282bdbf8f8bce4094369a2d1e4b5645e9 ]

The DSI host has different modes in prepare() and enable() functions,
prepare() is in LP command mode and enable() is in HS video mode.

>From our experience, generally the initialization sequence needs to be
sent in the LP command mode.

Move the setup init function from enable() to prepare() to fix a display
shift on rk3568 evb.

Tested on rk3568/rk3576/rk3588 EVB.

Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250618091520.691590-1-andyshrk@163.com
Signed-off-by: Sasha Levin <sashal@kernel.org>