qemu-arm and libsdl-native are not in HOSTTOOLS, so there's no point in
checking that they're on PATH.
Also qemu uses pkg-config to find SDL, so libsdl-native isn't required.
(From OE-Core rev: a8d8b0d9e1c2346d5a314ed0a7bf5be66044a51d)
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>