Some build systems (notably, Meson) like to be told when cross-compiling
what the target endian and word size is. We don't have these exported
via the variables, so add them using siteinfo as a source of data.
(From OE-Core rev: c2fee816cae6dbedcb40f15be4a1b9ee91757a64)
Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>