The board/altera/socfpga directory is not a generic SoCFPGA machine
anymore, but instead it represents the Altera SoCDK board. To make
matters more complicated, it represents both CycloneV and ArriaV
variant.

On the other hand, nowadays, the content of this board directory is
mostly comprised of QTS-generated header files, while all the generic
code is in arch/arm/mach-socfpga already.

Thus, this patch splits the board/altera/socfpga into a separate
board directory for ArriaV SoCDK and CycloneV SoCDK, so that each
can be populated with the correct QTS-generated header files for
that particular board.
Signed-off-by: NMarek Vasut <marex@denx.de>

The CONFIG_TARGET_SOCFPGA_CYCLONE5 and CONFIG_TARGET_SOCFPGA_ARRIA5
selected both a board and a CPU. This is not correct as these macros
are supposed to select only board.

All would be good, if QTS-generated header files didn't check for
these macros exactly to determine if the platform is Cyclone V or
Arria V. Thus, for the sake of compatibility with not well fleshed
out header file generator, this patch makes these two macros into
a stub config option and introduces new CONFIG_TARGET_SOCFPGA_CYCLONE5_SOCDK
and CONFIG_TARGET_SOCFPGA_ARRIA5_SOCDK targets, which select the
previous stub config option.

The result is that compatibility with QTS is preserved and the new
CONFIG_TARGET_* select actual target boards.
Signed-off-by: NMarek Vasut <marex@denx.de>

By making the board selections optional, every defconfig will include
the board selection when running savedefconfig so if a new board is
added to the top of the list of choices the former top's defconfig will
still be correct.
Signed-off-by: NJoe Hershberger <joe.hershberger@ni.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NStephen Warren <swarren@wwwdotorg.org>
Cc: Tom Rini <trini@konsulko.com>

Switch to a more standard way of board select; put the SoC select
into arch/arm/Kconfig and move the board select menu under
arch/arm/mach-socfpga/Kconfig.

Also, consolidate SYS_BOARD, SYS_VENDOR, SYS_SOC, SYS_CONFIG_NAME.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>