nrf52: add support for GPIO interrupts
nrf52: add macros to decode GPIO PIN and GPIO PORT
nrf52: various cosmetic changes
nrf52: fix GPIO P1 memory address
boards/nrf52840-dk: add support for SPI
boards/nrf52840-dk: add support for LSM6DSL sensor
boards/nrf52840-dk: add support for SX127X radio
nrf52 updates
board/arm/nrf52/nrf52832-dk: use the on-board virtual COM pins as default UART0 configuration
board/arm/nrf52: initial support for the nrf52840-dk board
board/arm/nrf52: initial support for the nrf52840-dk dongle board
arch/arm/src/nrf52: add support for port 1 GPIO
arch/arm/src/nrf52: initial support for UART1
arch/arm/src/nrf52: add UICR definitions
Approved-by: Gregory Nutt <gnutt@nuttx.org>