dm: gpio: add BCM6345 gpio driver

This driver is based on linux/arch/mips/bcm63xx/gpio.c, simplified to allow
defining one or two independent banks for each Broadcom SoC.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
3 files changed