nand: brcmnand: add iproc support

Add support for the iproc Broadcom NAND controller,
used in Northstar SoCs for example. Based on the Linux
driver.

Cc: Philippe Reynes <philippe.reynes@softathome.com>
Cc: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Reviewed-by: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: William Zhang <william.zhang@broadcom.com>
Link: https://lore.kernel.org/all/20230308214231.378013-1-linus.walleij@linaro.org/


Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>