clocksource/drivers/sprd: Fix Kconfig dependency

SPRD arch doesn't select SPRD_TIMER, so this config would not
appear even if ARCH_SPRD is set but COMPILE_TEST not.

Fix the dependency of this config with SPRD arch, and set a
default value for it, also leave other choices for EXPERT.
Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

drivers/clocksource/Kconfig

@@ -450,8 +450,10 @@ config MTK_TIMER
 	  Support for Mediatek timer driver.
 
 config SPRD_TIMER
-	bool "Spreadtrum timer driver" if COMPILE_TEST
+	bool "Spreadtrum timer driver" if EXPERT
 	depends on HAS_IOMEM
+	depends on (ARCH_SPRD || COMPILE_TEST)
+	default ARCH_SPRD
 	select TIMER_OF
 	help
 	  Enables support for the Spreadtrum timer driver.