MIPS: generic: Update node names to avoid unit addresses

With the latest mkimage from U-Boot 2021.04, the generic defconfigs no
longer build, failing with:

/usr/bin/mkimage: verify_header failed for FIT Image support with exit code 1

This is expected after the linked U-Boot commits because '@' is
forbidden in the node names due to the way that libfdt treats nodes with
the same prefix but different unit addresses.

Switch the '@' in the node name to '-'. Drop the unit addresses from the
hash and kernel child nodes because there is only one node so they do
not need to have a number to differentiate them.

Cc: stable@vger.kernel.org
Link: https://source.denx.de/u-boot/u-boot/-/commit/79af75f7776fc20b0d7eb6afe1e27c00fdb4b9b4
Link: https://source.denx.de/u-boot/u-boot/-/commit/3f04db891a353f4b127ed57279279f851c6b4917
Suggested-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: generic: Add support for MIPSfpga

Add support for the MIPSfpga platform to generic kernel.

Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15846/
[jhogan@kernel.org: Use separate board-xilfpga.its.S. Add 32r2 and
little endian requires to board-xilfpga.config]
Signed-off-by: James Hogan <jhogan@kernel.org>