cfg: add omapl138 support and da850evm preliminary support

cfg: add omapl138 support and da850evm preliminary support

This patch adds support for the omapl138 target and preliminary support for the da850evm. The
target cfg file is based on the icepick routing done by the target/ti_dm6446.cfg file.

I have performed limited testing with this setup. I am posting this patch in the interest of
sharing cfg files and in the hopes that the experts on this list can correct errors I have made or
point out enhancements.

The testing I have performed is debugging uboot with gdb where I also use the following local.cfg
and gdbinit files. Debugging appears to work in so much as 'ni' works.

local.cfg:
gdb_memory_map disable

gdbinit:
target remote localhost:3333
set remote hardware-breakpoint-limit 2
set remote hardware-watchpoint-limit 2
monitor poll on

Comments welcome.

Best Regards,
Ben Gardiner