checkpatch: refactor 'allowed asm includes' and add memory.h

Change the check suggesting replacement of asm-includes with
linux-includes.  Exceptions to this rule are easier to extend now.  Add
memory.h because ARM has a custom one.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/checkpatch.pl

@@ -224,6 +224,12 @@ our @modifierList = (
 	qr{fastcall},
 );
 
+our $allowed_asm_includes = qr{(?x:
+	irq|
+	memory
+)};
+# memory.h: ARM has a custom one
+
 sub build_types {
 	my $mods = "(?x:  \n" . join("|\n  ", @modifierList) . "\n)";
 	my $all = "(?x:  \n" . join("|\n  ", @typeList) . "\n)";
@@ -2308,7 +2314,7 @@ sub process {
 			my $checkfile = "include/linux/$file";
 			if (-f "$root/$checkfile" &&
 			    $realfile ne $checkfile &&
-			    $1 ne 'irq')
+			    $1 !~ /$allowed_asm_includes/)
 			{
 				if ($realfile =~ m{^arch/}) {
 					CHK("Consider using #include <linux/$file> instead of <asm/$file>\n" . $herecurr);