ARC: build: Try to guess GCC variant of cross compiler

stable inclusion
from stable-v6.6.70
commit f2b94ee08ec66c5b1cb13e6289ee3bbef35c1cdb
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IBOHV1

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f2b94ee08ec66c5b1cb13e6289ee3bbef35c1cdb

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[ Upstream commit 824927e88456331c7a999fdf5d9d27923b619590 ]

ARC GCC compiler is packaged starting from Fedora 39i and the GCC
variant of cross compile tools has arc-linux-gnu- prefix and not
arc-linux-. This is causing that CROSS_COMPILE variable is left unset.

This change allows builds without need to supply CROSS_COMPILE argument
if distro package is used.

Before this change:
$ make -j 128 ARCH=arc W=1 drivers/infiniband/hw/mlx4/
  gcc: warning: ‘-mcpu=’ is deprecated; use ‘-mtune=’ or ‘-march=’ instead
  gcc: error: unrecognized command-line option ‘-mmedium-calls’
  gcc: error: unrecognized command-line option ‘-mlock’
  gcc: error: unrecognized command-line option ‘-munaligned-access’

[1] https://packages.fedoraproject.org/pkgs/cross-gcc/gcc-arc-linux-gnu/index.html


Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Wen Zhiwei <wenzhiwei@kylinos.cn>