drm/i915/dsi: Remove GPIO lookup table at the end of intel_dsi_vbt_gpio_init()

To properly deal with GPIOs used in MIPI panel sequences a temporary
GPIO lookup will be used. Since there can only be 1 GPIO lookup table
for the "0000:00:02.0" device this will not work if the GPIO lookup
table used by intel_dsi_vbt_gpio_init() is still registered.

After getting the "backlight" and "panel" GPIOs the lookup table
registered by intel_dsi_vbt_gpio_init() is no longer necessary,
remove it so that another temporary lookup-table for the "0000:00:02.0"
device can be added.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231103201831.1037416-10-andriy.shevchenko@linux.intel.com