Revert "checkpatch: add check for keyword 'boolean' in Kconfig definitions"

This reverts commit 327953e9.

You cannot use 'boolean' since commit b92d804a ("kconfig: drop
'boolean' keyword").

This check is no longer needed.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Joe Perches <joe@perches.com>

scripts/checkpatch.pl

@@ -3390,13 +3390,6 @@ sub process {
 			}
 		}
 
-# discourage the use of boolean for type definition attributes of Kconfig options
-		if ($realfile =~ /Kconfig/ &&
-		    $line =~ /^\+\s*\bboolean\b/) {
-			WARN("CONFIG_TYPE_BOOLEAN",
-			     "Use of boolean is deprecated, please use bool instead.\n" . $herecurr);
-		}
-
 		if (($realfile =~ /Makefile.*/ || $realfile =~ /Kbuild.*/) &&
 		    ($line =~ /\+(EXTRA_[A-Z]+FLAGS).*/)) {
 			my $flag = $1;