On 32-bit hosts op_qemu_ld32s is unused. Remove it to fix the
following assertion failure:

qemu-alpha: tcg/tcg.c:1055:
tcg_add_target_add_op_defs: Assertion `tcg_op_defs[op].used' failed.
Signed-off-by: NJay Foad <jay.foad@gmail.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>