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

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 <[email protected]>
Signed-off-by: Vineet Gupta <[email protected]>

Author: rleon

arch/arc/Makefile

@@ -6,7 +6,7 @@
 KBUILD_DEFCONFIG := haps_hs_smp_defconfig
 
 ifeq ($(CROSS_COMPILE),)
-CROSS_COMPILE := $(call cc-cross-prefix, arc-linux- arceb-linux-)
+CROSS_COMPILE := $(call cc-cross-prefix, arc-linux- arceb-linux- arc-linux-gnu-)
 endif
 
 cflags-y	+= -fno-common -pipe -fno-builtin -mmedium-calls -D__linux__