MIPS: Move identification of VP(E) into proc.c from smp-mt.c

MIPS: Move identification of VP(E) into proc.c from smp-mt.c

The addition of VPE information to /proc/cpuinfo used to be in smp-mt.c.
This file is not used by MIPS r6 kernels, so the Virtual Processor
information was not present for these CPU types.

Move the code to print VPE information into proc.c, add a case for MIPS
r6 CPUS, and remove the block from smp-mt.c.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Cc: Qais Yousef <qsyousef@gmail.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13847/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>