Add a compatible string for the NVIDIA Denver CPU to the ARM CPU DT
binding documentation file.  The primary objective here is to keep
checkpatch.pl from warning when the compatible string is used in an
SoC DT file, per:

http://marc.info/?l=linux-tegra&m=142201349727836&w=2

This second version changes the string from "nvidia,denver" to
"nvidia,tegra132-denver" to more precisely describe the revision of
the Denver CPU complex that is present in the Tegra132 SoC.
Signed-off-by: NPaul Walmsley <paul@pwsan.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Rohit Vaswani <rvaswani@codeaurora.org>
Cc: Paul Walmsley <pwalmsley@nvidia.com>
Cc: Marc Carino <marc.ceeeee@gmail.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: NRob Herring <robh@kernel.org>