arm64: sparx5: Add support for Microchip 2xA53 SoC

This adds support for the Microchip Sparx5 ARMv8-based SoC family of
TSN-capable gigabit switches.

Link: https://lore.kernel.org/r/20200615133242.24911-3-lars.povlsen@microchip.com


Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Lars Povlsen <lars.povlsen@microchip.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>