Merge pull request #2265 from jfischer-phytec-iot/pr@kinetis_common

cpu/kinetis_common/Makefile

cpu/kinetis_common/Makefile.include

cpu/kinetis_common/adc.c

cpu/kinetis_common/cpuid.c

cpu/kinetis_common/doc.txt

cpu/kinetis_common/gpio.c

cpu/kinetis_common/hwtimer_arch.c

cpu/kinetis_common/i2c.c

cpu/kinetis_common/include/hwtimer_cpu.h

cpu/kinetis_common/include/mcg.h

cpu/kinetis_common/mcg.c

cpu/kinetis_common/pwm.c

cpu/kinetis_common/random_rnga.c

cpu/kinetis_common/random_rngb.c

cpu/kinetis_common/rtc.c

cpu/kinetis_common/spi.c

cpu/kinetis_common/timer.c

cpu/kinetis_common/uart.c