clk: Hi6220: enable stub clock driver for ARCH_HISI

In current kernel config 'CONFIG_STUB_CLK_HI6220' is disabled by
default, as result stub clock driver has not been registered and
CPUFreq driver cannot work.

This patch is to enable stub clock driver in config for ARCH_HISI.
Reported-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

drivers/clk/hisilicon/Kconfig

@@ -39,5 +39,6 @@ config RESET_HISI
 config STUB_CLK_HI6220
 	bool "Hi6220 Stub Clock Driver"
 	depends on COMMON_CLK_HI6220 && MAILBOX
+	default ARCH_HISI
 	help
 	  Build the Hisilicon Hi6220 stub clock driver.