Swap half-words (16-bit) and words (32-bit) within a larger value.
Mirrors functions of the same names within include/qemu/bitops.h.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: David Miller <dmiller423@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20220428094708.84835-5-david@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>