Also use the glibc override instead of target overrides and remove
distro overrides creating variables that can be overridden instead.
(From OE-Core rev: ab046b02adc523735ffd61b530130a8c967f9569)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>