gcc-common: Enable building multiarch mips gcc

gcc-common: Enable building multiarch mips gcc

MIPS gcc is not configured with multiarch enabled.  This causes
compiler generates local label with $ prefix, which is specified
in default o32 abi.  It is not recognized as local symbol by n64
assembler, so we get a lot of unexpected external symbols.  We
should configure MIPS gcc with --enable-targets=all, as for other
archs.

(From OE-Core rev: c210393b3e0c54606493e311d7c2040efebc4dcd)

Signed-off-by: Lei Liu <lei.liu2@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>