MIPS: Fix for warning from FPU emulation code

MIPS: Fix for warning from FPU emulation code

The default implementation of 'cpu_has_fpu' macro calls
smp_processor_id() which causes this warning to be printed when
preemption is enabled:

[    4.664000] Algorithmics/MIPS FPU Emulator v1.5
[    4.676000] BUG: using smp_processor_id() in preemptible [00000000] code: ini
[    4.700000] caller is fpu_emulator_cop1Handler+0x434/0x27b8

This problem got introduced in November 2009 by
af1d2af877ef6c36990671bc86a5b9c5bb50b1da (lmo) [MIPS: Fix emulation of
64-bit FPU on 64-bit CPUs.] rsp.  da0bac33413b2888d3623dad3ad19ce76b688f07
(kernel.org) [MIPS: Fix emulation of 64-bit FPU on FPU-less 64-bit CPUs.]
in 2.6.32.

Fixed by rewriting cop1_64bit() to return a constant whenever possible
but most importantly avoid the use pf cpu_has_fpu entirely.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reported-by: Jayachandran C <jchandra@broadcom.com>
Initial-patch-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: https://patchwork.linux-mips.org/patch/4225/