ARC: change defconfig defaults to ARCv2

ARC: change defconfig defaults to ARCv2

BugLink: https://bugs.launchpad.net/bugs/1837161
commit b7cc40c32a8bfa6f2581a71747f6a7d491fe43ba upstream.

Change the default defconfig (used with 'make defconfig') to the ARCv2
nsim_hs_defconfig, and also switch the default Kconfig ISA selection to
ARCv2.

This allows several default defconfigs (e.g. make defconfig, make
allnoconfig, make tinyconfig) to all work with ARCv2 by default.

Note since we change default architecture from ARCompact to ARCv2
it's required to explicitly mention architecture type in ARCompact
defconfigs otherwise ARCv2 will be implied and binaries will be
generated for ARCv2.

Cc: <stable@vger.kernel.org> # 4.4.x
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>