aarch64: filter $x from kallsyms

Similar to ARM, AArch64 is generating $x and $d syms... which isn't
terribly helpful when looking at %pF output and the like. Filter those
out in kallsyms, modpost and when looking at module symbols.

Seems simplest since none of these check EM_ARM anyway, to just add it
to the strchr used, rather than trying to make things overly
complicated.

initcall_debug improves:
dmesg_before.txt: initcall $x+0x0/0x154 [sg] returned 0 after 26331 usecs
dmesg_after.txt: initcall init_sg+0x0/0x154 [sg] returned 0 after 15461 usecs

Signed-off-by: Kyle McMartin <kyle@redhat.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/kernel/module.c b/kernel/module.c
index 03214bd2..3d52936 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3388,7 +3388,7 @@
 {
 	if (str[0] == '.' && str[1] == 'L')
 		return true;
-	return str[0] == '$' && strchr("atd", str[1])
+	return str[0] == '$' && strchr("axtd", str[1])
 	       && (str[2] == '\0' || str[2] == '.');
 }