Also renamed TOP to ELFTCDIR as used elsewhere in ELF Tool Chain build bits to avoid confusion.

Unfortunately ELFTCDIR is too long and it looks odd with a tab after, unless SRCDIR below gets indented an extra tab, and then PACKAGE= looks out of place:

PACKAGE=lib${LIB}
ELFTCDIR=       ${SRCTOP}/contrib/elftoolchain
SRCDIR=         ${ELFTCDIR}/libdwarf

It's needed for < > includes relative to ..