qemu: Add fix for powerpc instruction fallback issue

See the patch for more details, fixes a regression in qemu causing
illegal instructions in libm on powerpc, triggered by a libinput
upgrade.

https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=f1c56cdff09f650ad721fae026eb6a3651631f3d


was the glibc code generating the instruction and triggering the issue.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Steve Sakoman <steve@sakoman.com>