sparc64: Delete now unused user copy assembler helpers.

[ Upstream commit 614da3d9685b67917cab48c8452fd8bf93de0867 ]

All of __ret{,l}_mone{_asi,_fp,_asi_fpu} are now unused.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>