ARM: SAMSUNG: Do not register legacy timer interrupts on Exynos

This patch removes legacy PWM timer interrupt initialization from
exynos{4,5}_init_irq() functions, since it conflicts with internal
interrupt handling of the new PWM clocksource driver.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Olof Johansson <olof@lixom.net>