ARM: late Exynos multiplatform changes

These continue the multiplatform support for exynos, adding support
for building most of the essential drivers (clocksource, clk, irqchip)
when combined with other platforms. As a result, it should become
really easy to add full multiplatform exynos support in 3.11, although
we don't yet enable it for 3.10.

The changes were not included in the earlier multiplatform series
in order to avoid clashes with the other Exynos updates.

This also includes work from Tomasz Figa to fix the pwm clocksource
code on Exynos, which is not strictly required for multiplatform,
but related to the other patches in this set and needed as a bug
fix for at least one board.
Merge branch 'exynos/pwm-clocksource' into late/multiplatform

This series from Tomasz Figa restores support for the pwm clocksource
in Exynos, which was broken during the conversion of the platform
to the common clk framework. The clocksource is only used in one
board in the mainline kernel (universal_c210), and this makes it
work for DT based probing as well as restoring the non-DT based
case.

* exynos/pwm-clocksource:
  ARM: dts: exynops4210: really add universal_c210 dts
  ARM: dts: exynos4210: Add basic dts file for universal_c210 board
  ARM: dts: exynos4: Add node for PWM device
  ARM: SAMSUNG: Do not register legacy timer interrupts on Exynos
  clocksource: samsung_pwm_timer: Work around rounding errors in clockevents core
  clocksource: samsung_pwm_timer: Correct programming of clock events
  clocksource: samsung_pwm_timer: Use proper clockevents max_delta
  clocksource: samsung_pwm_timer: Add support for non-DT platforms
  clocksource: samsung_pwm_timer: Drop unused samsung_pwm struct
  clocksource: samsung_pwm_timer: Keep all driver data in a structure
  clocksource: samsung_pwm_timer: Make PWM spinlock global
  clocksource: samsung_pwm_timer: Let platforms select the driver
  Documentation: Add device tree bindings for Samsung PWM timers
  clocksource: add samsung pwm timer driver

Conflicts:
	arch/arm/boot/dts/Makefile
	arch/arm/mach-exynos/common.c
	drivers/clocksource/Kconfig
	drivers/clocksource/Makefile

Signed-off-by: Arnd Bergmann <arnd@arndb.de>