monkey: Remove buildpaths from generated mk_env.h
It has paths to compiler and assembler which are technically cross
compilers in OE. We do have these names symlinked on target too but
paths needs to be removed.
Fixes
WARNING: monkey-1.6.9-r0 do_package_qa: QA Issue: File /usr/include/monkey/mk_env.h in package monkey-dev contains reference to TMPDIR [buildpaths]
Signed-off-by: Khem Raj <raj.khem@gmail.com>