clocksource: exynos_mct: Move one-shot check from tick clear to ISR

clocksource: exynos_mct: Move one-shot check from tick clear to ISR

When a timer tick occurs and the clock is in one-shot mode, the timer
needs to be stopped to prevent it triggering subsequent interrupts.
Currently this code is in exynos4_mct_tick_clear(), but as it is
only needed when an ISR occurs move it into exynos4_mct_tick_isr(),
leaving exynos4_mct_tick_clear() just doing what its name suggests it
should.

Signed-off-by: Stuart Menefy <stuart.menefy@mathembedded.com>
[pending patch for mainline]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Change-Id: I1004b6947a338d27dc629f4174607663dedc1f33