ARM: s3c64xx: select power domains only when used

The power domain code is only available when CONFIG_PM
is enabled, so we must not select that unconditionally for
s3c64xx. Changing it to 'select PM_GENERIC_DOMAINS if PM'
mirrors what we do on other platforms, and fixes a possible
randconfig build bug.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Cc: Tomasz Figa <tomasz.figa@gmail.com>
Cc: Ben Dooks <ben-linux@fluff.org>

arch/arm/Kconfig

@@ -766,7 +766,7 @@ config ARCH_S3C64XX
 	select HAVE_TCM
 	select NO_IOPORT
 	select PLAT_SAMSUNG
-	select PM_GENERIC_DOMAINS
+	select PM_GENERIC_DOMAINS if PM
 	select S3C_DEV_NAND
 	select S3C_GPIO_TRACK
 	select SAMSUNG_ATAGS