Correct ranges in Armada38x dts

Ranges property of 'soc' node used two-cell addresses which resulted in
casting errors as simplebus resource allocation works with 32-bit u_long
variables. FDT ranges were simplified.

Reviewed by: imp
Obtained from: Semihalf
Sponsored by: Stormshield
Submitted by: Michal Stanek <mst@semihalf.com>
Differential revision: https://reviews.freebsd.org/D4212