ARC: make generic print_cpuinfo() weak

This allows board to override print_cpuinfo() because
they might know better which ARChitect template was used.
This way we may not only derive base architecture type and
version but more meaningful things like "ARC EM7D" instead of
simple "ARC EM", "ARC HS36" instead of "ARC HS".

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

arch/arc/lib/cpu.c

@@ -60,7 +60,7 @@ const char *decode_identity(void)
 	}
 }
 
-int print_cpuinfo(void)
+__weak int print_cpuinfo(void)
 {
 	printf("CPU:   %s\n", decode_identity());
 	return 0;