soc: rockchip: Restrict to ARCH_ROCKCHIP

By definition this directory contains drivers that are specific to the
Rockchip architecture. All Kconfig options should therefore depend on
ARCH_ROCKCHIP to avoid exposing these symbols on other architectures.
For example, this options currently shows up as new when doing an
incremental build on PowerPC.
Signed-off-by: NThierry Reding <treding@nvidia.com>

[add COMPILE_TEST alternative condition]
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>

drivers/soc/rockchip/Kconfig

+if ARCH_ROCKCHIP || COMPILE_TEST
+
 #
 # Rockchip Soc drivers
 #
@@ -12,3 +14,5 @@ config ROCKCHIP_PM_DOMAINS
           mode. The RK3288 PMU is dedicated for managing the power of the whole chip.
 
           If unsure, say N.
+
+endif