Configure CPU window to second CESA SRAM

Check if there is a second CESA SRAM node in FDT and add a CPU window
for it. Define A38X specific macro for setting device attribute for
each node.

Submitted by: Michal Stanek <mst@semihalf.com>
Obtained from: Semihalf
Sponsored by: Stormshield
Differential revision: https://reviews.freebsd.org/D6216