regulator: rpi-panel-v2: Fix missing OF dependency

regulator: rpi-panel-v2: Fix missing OF dependency

Add missing OF dependency and drop of_match_ptr() use.
This fixes the following LKP report:

"
>> drivers/regulator/rpi-panel-v2-regulator.c:95:34: warning: 'rpi_panel_v2_dt_ids' defined but not used [-Wunused-const-variable=]
    static const struct of_device_id rpi_panel_v2_dt_ids[] = {
                                     ^~~~~~~~~~~~~~~~~~~
"

Fixes: d49305862fdc ("regulator: rpi-panel-v2: Add regulator for 7" Raspberry Pi 720x1280")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202506100440.fyTGO7CG-lkp@intel.com/
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Link: https://patch.msgid.link/20250609223012.87764-1-marek.vasut+renesas@mailbox.org
Signed-off-by: Mark Brown <broonie@kernel.org>