Commit 793a137a (target-sparc:
Implement BMASK/BSHUFFLE.) introduced a stray usage of softfloat uint64
type.

Use uint64_t instead.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>