gitlint: match max title length restriction with checkpatch

Match the restriction on title length with checkpatch, since we document
that we follow the Linux style and checkpatch was there before gitlint.

Fixes #14652

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

.gitlint

@@ -13,7 +13,7 @@ debug = false
 extra-path=scripts/gitlint
 
 [title-max-length-no-revert]
-line-length=72
+line-length=75
 
 [body-min-line-count]
 min-line-count=1