libc/newlib: fix host/target confusion

newlib handles the build/host/target a bit differently as one would expect:
build : not used
host : the nachine that builds newlib
target : the machine on which newlib will run

reporter_name="unknown"

reporter_url="http://iphonelinux.org/index.php/Glibc_toolchain_using_crosstool-NG"

reporter_comment="An (experimental) toolchain targeting the Apple's iPhone."