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 <[e-mail]>
Closes: https://lore.kernel.org/oe-kbuild-all/[e-mail]/
Signed-off-by: Marek Vasut <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/Kconfig

···
 config REGULATOR_RASPBERRYPI_TOUCHSCREEN_V2
 	tristate "Raspberry Pi 7-inch touchscreen panel V2 regulator"
 	depends on GPIOLIB
-	depends on I2C
+	depends on I2C && OF
 	select GPIO_REGMAP
 	select REGMAP_I2C
 	help

drivers/regulator/rpi-panel-v2-regulator.c

···
 	.driver = {
 		.name = "rpi_touchscreen_v2",
 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
-		.of_match_table = of_match_ptr(rpi_panel_v2_dt_ids),
+		.of_match_table = rpi_panel_v2_dt_ids,
 	},
 	.probe = rpi_panel_v2_i2c_probe,
 };