armv8l is always 32-bit and should implement the armv7 ISA, so
just use the same filename as for armv7.
This avoids wrongly building a 64-bit binary because of an incorrect assumption
of what 'armv8l' is (a 32-bit system).
Obviously, we should not then build a 64-bit (arm64) binary. Especially
given armv8l is often used in arm32-on-arm64 chroots to build stuff for
weaker-powered arm32 devices.
Signed-off-by: Sam James <sam@gentoo.org>
