Moving HICs to use CMSIS UART Drivers

[mbrossard]

Based on @flit's work on lpc55xx. Using kl27z as an example.

(ping @gerargz, @microbit-carlos)

[0Grit]

I love the smell of progress.

[tarokajya]

Just quick information. The original lpc55xx/uart.c contains typo around line 109.

    case UART_DATA_BITS_7:
        control |= ARM_USART_DATA_BITS_6;
        break;

ARM_USART_DATA_BITS_6 has to be ARM_USART_DATA_BITS_7, I think.

[mathias-arm]

@tarokajya: nice catch, I opened #888 for that (and other) typos.