Allow parallel builds by building each library and program in turn.
This is slightly less parallelism than ideal, but it works.
Add a SYSROOT prefix to /usr/local to allow us to use packages in our
sysroot.
Swap MK_SOAAP conditional to match tshark Makefile
Build minishark and tshark static.

It is now possible to build minishark and tshark staticaly on MIPS with
CHERI clang if you replace the SDK's ld with a newer one.