ARM: new platform for Energy Micro's EFM32 Cortex-M3 SoCs

There are still some missing parts (e.g. board support, device trees),
but with these bits added on top of this patch I can successfully boot a
EFM32GG-DK3750 board that uses an EFM32GG990F1024.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

diff --cc arch/arm/Kconfig
Simple merge

diff --cc arch/arm/Makefile
Simple merge

diff --cc arch/arm/configs/efm32_defconfig
Simple merge

diff --cc arch/arm/mach-efm32/Makefile
Simple merge

diff --cc arch/arm/mach-efm32/Makefile.boot
Simple merge

diff --cc arch/arm/mach-efm32/dtmachine.c
Simple merge

diff --cc arch/arm/mach-efm32/include/mach/entry-macro.S
Simple merge

diff --cc arch/arm/mach-efm32/include/mach/timex.h
Simple merge