checkpatch: kconfig: recognize more prompts when checking help texts

The check for a missing or short help text only considers symbols with a
prompt, but doesn't recognize any of the following as a prompt:

	bool 'foo'
	tristate 'foo'
	prompt "foo"
	prompt 'foo'

Make the check recognize those too.

Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 3d40403..2b40431 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2812,7 +2812,7 @@
 				next if ($f =~ /^-/);
 				last if (!$file && $f =~ /^\@\@/);
 
-				if ($lines[$ln - 1] =~ /^\+\s*(?:bool|tristate)\s*\"/) {
+				if ($lines[$ln - 1] =~ /^\+\s*(?:bool|tristate|prompt)\s*["']/) {
 					$is_start = 1;
 				} elsif ($lines[$ln - 1] =~ /^\+\s*(?:---)?help(?:---)?$/) {
 					$length = -1;