cpu/arm/k60: onewire: Remove unnecessary #include

Signed-off-by: Joakim Gebart <joakim.gebart@eistec.se>
cpu/arm/k60: Disable unimplemented clock functions

Disabled clock_wait and clock_delay because of missing implementations.
Added preliminary implementation of clock_wait, but disabled because
of no users yet.

Signed-off-by: Joakim Gebart <joakim.gebart@eistec.se>
cpu/arm/k60: Inline power mode helper functions.

 - Added inline keyword to wait() and stop() used inside power-modes.c
 - Replaced asm("WFI") by __WFI() (CMSIS instruction/function).

Signed-off-by: Joakim Gebart <joakim.gebart@eistec.se>
cpu/arm/k60: ADC: remove ugly getter.

Replaced getter inline function with array of pointers in ROM.
Side effect: This removes the range checking on adc_num.

Signed-off-by: Joakim Gebart <joakim.gebart@eistec.se>