linux-yocto: Enable powerpc-debug fragment for ppc64 LE
qemuppc64 is LE by default, this fixes kernel build for qemuppc64 with gcc12 Signed-off-by: Khem Raj <raj.khem@gmail.com> Cc: Bruce Ashfield <bruce.ashfield@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>