feat(plat/marvell/a3k): add north and south bridge reset registers

These registers make it is possible to do external resets of A3700
peripherals. Most peripherals are reset by clearing a particular bit,
but some need setting the bit. Reflect this via "_N" suffix in macro
names.

Signed-off-by: Pali Rohár <pali@kernel.org>
Change-Id: Iacef5e671746b831b5beea9e4fdcc59d8de84edc
1 file changed