regulator: stm32-booster: Fix W=1 build warning when CONFIG_OF=n

Fix below warning when CONFIG_OF=n:

drivers/regulator/stm32-booster.c:104:34: warning: ‘stm32_booster_of_match’ defined but not used [-Wunused-const-variable=]
104 | static const struct of_device_id stm32_booster_of_match[] = {
| ^~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Jisheng Zhang <[e-mail]>
Acked-by: Fabrice Gasnier <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/stm32-booster.c

···
 	return 0;
 }
 
-static const struct of_device_id stm32_booster_of_match[] = {
+static const struct of_device_id __maybe_unused stm32_booster_of_match[] = {
 	{
 		.compatible = "st,stm32h7-booster",
 		.data = (void *)&stm32h7_booster_desc