clocksource/atmel-st: Add 'depends on HAS_IOMEM' to fix unmet dependency

The ATMEL_ST config selects MFD_SYSCON, but does not depend on HAS_IOMEM.

Compile testing on architecture without HAS_IOMEM causes "unmet direct
dependencies" in Kconfig phase. Detected by "make ARCH=score allyesconfig".

Add the proper dependency to the ATMEL_ST config.

Signed-off-by: Masahiro Yamada <[e-mail]>
Signed-off-by: Thomas Gleixner <[e-mail]>
Cc: Daniel Lezcano <[e-mail]>
Cc: Arnd Bergmann <[e-mail]>
Link: https://lkml.kernel.org/r/[e-mail]

drivers/clocksource/Kconfig

···
 
 config ATMEL_ST
 	bool "Atmel ST timer support" if COMPILE_TEST
+	depends on HAS_IOMEM
 	select TIMER_OF
 	select MFD_SYSCON
 	help