Define strndupa if not available in libc additionally fix headers
to explicitly needed include files which glibc was including indirectly
(From OE-Core rev: 24097d8bb481ed1312c45b2e93527a271f56e4be)
Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>