firmware: scpi: add CONFIG_OF dependency

We get a harmless warning if the ARM_SCPI_POWER_DOMAIN driver is enabled
without CONFIG_OF during compile testing:

warning: (ARM_SCPI_POWER_DOMAIN) selects PM_GENERIC_DOMAINS_OF which has unmet direct dependencies (PM_GENERIC_DOMAINS && OF)

There is no need to select PM_GENERIC_DOMAINS_OF if OF is set, so we can
replace the 'select' with a dependency.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 8bec4337ad40 ("firmware: scpi: add device power domain support using genpd")
Acked-by: Sudeep Holla <sudeep.holla@arm.com>

drivers/firmware/Kconfig

@@ -29,10 +29,9 @@ config ARM_SCPI_PROTOCOL
 
 config ARM_SCPI_POWER_DOMAIN
 	tristate "SCPI power domain driver"
-	depends on ARM_SCPI_PROTOCOL || COMPILE_TEST
+	depends on ARM_SCPI_PROTOCOL || (COMPILE_TEST && OF)
 	default y
 	select PM_GENERIC_DOMAINS if PM
-	select PM_GENERIC_DOMAINS_OF if PM
 	help
 	  This enables support for the SCPI power domains which can be
 	  enabled or disabled via the SCP firmware