Corrected bitmask for IOCON_SWDIO_PIO1_3_FUNC_CT32B1_MAT2, added mode definitions
Added initialisation code for ADC4, ADC5, ADC6 and ADC7. ADC5, ADC6, ADC7 are
disabled for various reasons on r0ket.
Added error return values for overrun and wrong ADC. Added check for ADC selection on r0ket.