pmdomain: rockchip: add regulator dependency

When CONFIG_REGULATOR is disabled, this pmdomain driver fails to build:

drivers/pmdomain/rockchip/pm-domains.c:653:30: error: implicit declaration of function 'devm_of_regulator_get'; did you mean 'devm_regulator_get'? [-Wimplicit-function-declaration]
  653 |                 pd->supply = devm_of_regulator_get(pmu->dev, pd->node, "domain");
      |                              ^~~~~~~~~~~~~~~~~~~~~
      |                              devm_regulator_get
drivers/pmdomain/rockchip/pm-domains.c:653:28: error: assignment to 'struct regulator *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
  653 |                 pd->supply = devm_of_regulator_get(pmu->dev, pd->node, "domain");
      |                            ^

Add a Kconfig dependency.

Fixes: db6df2e ("pmdomain: rockchip: add regulator support")
Signed-off-by: Arnd Bergmann <[email protected]>
Reviewed-by: Sebastian Reichel <[email protected]>
Reviewed-by: Dragan Simic <[email protected]>
Reviewed-by: Heiko Stuebner <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Ulf Hansson <[email protected]>

Author: arndb

drivers/pmdomain/rockchip/Kconfig

@@ -5,6 +5,7 @@ config ROCKCHIP_PM_DOMAINS
 	bool "Rockchip generic power domain"
 	depends on PM
 	depends on HAVE_ARM_SMCCC_DISCOVERY
+	depends on REGULATOR
 	select PM_GENERIC_DOMAINS
 	help
 	  Say y here to enable power domain support.