modpost: Ignore ARC specific non-alloc sections

ARC relocatable object files contain one/more .gnu.linkonce.arcextmap.*
sections (collated by kernel/vmlinux.lds into .arcextmap in final link).
This section is used by debuggers to display the extension instructions
and need-not be loaded by target (hence !SHF_ALLOC)

The final kernel binary only needs .arcextmap entry in modpost's ignore
list (section_white_list[]). However when building modules, modpost scans
each object file individually, hence tripping on non-aggregated
.gnu.linkonce.arcextmap.* entries as well.

Thus need for the 2 entires !

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

scripts/mod/modpost.c

@@ -830,6 +830,8 @@ static const char *section_white_list[] =
 	".toc*",
 	".xt.prop",				 /* xtensa */
 	".xt.lit",         /* xtensa */
+	".arcextmap*",			/* arc */
+	".gnu.linkonce.arcext*",	/* arc : modules */
 	NULL
 };