Revert "qemu.bbclass: Use the correct qemu binary in multilib cases"

Revert "qemu.bbclass: Use the correct qemu binary in multilib cases"

This reverts commit 9f5a6f89d9f4a6c7bed3b163e6eaa764d762f523.

The reason for reverting this is:
 * qemuwrapper has now a fallback method;
 * when using multilib, calling qemu_target_binary from recipes would
   always point to the qemu binary corresponding to the machine
   architecture. Hence, postinstalls needing to use qemu would call the
   wrong qemu user emulation binary;

(From OE-Core rev: 15408466515cec7cbb4c394aa203c87b6165f884)

Signed-off-by: Laurentiu Palcu <laurentiu.palcu@intel.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>