x86/cpufeatures: Add WBNOINVD feature definition

Add a new cpufeature definition for the WBNOINVD instruction.

The WBNOINVD instruction writes all modified cache lines in all levels of
the cache associated with a processor to main memory while retaining the
cached values.

Both AMD and Intel support this instruction.

Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
CC: David Woodhouse <dwmw@amazon.co.uk>
CC: Fenghua Yu <fenghua.yu@intel.com>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Ingo Molnar <mingo@redhat.com>
CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: Rudolf Marek <r.marek@assembler.cz>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/1541624211-32196-1-git-send-email-Janakarajan.Natarajan@amd.com