ARM: dts: aspeed: rainier: Add 4U device-tree

Add a device-tree for the Rainier 4U system. Change the model name
on the existing Rainier device-tree to 2U, and remove the two
extra power supplies that are only present on the 4U system. Also
add labels to the fan nodes for use in the 4U device-tree.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/20201028185647.14565-1-eajames@linux.ibm.com


Signed-off-by: Joel Stanley <joel@jms.id.au>