[PATCH RESEND] ARM: Kconfig: Select clocksource in STM32 entry

Maxime Coquelin [off-list ref] writes:

STM32 clocksource driver needs to be selected if ARCH_STM32.

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
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Hi Arnd,

  This patch applies on top of arm-soc's next/soc branch, so that you don't 
get conflicts with Stefan's ARM_SINGLE_ARMV7M patch.

Applied to next/soc,

Thanks,

Kevin