binman: allow '.' to be included in the missing blob tags

Extend the regex to add periods '.' in the tag so entries like
ti-fs-enc.bin can be represented in the missing-blob-help file.

Signed-off-by: Bryan Brattlof <bb@ti.com>

tools/binman/control.py

@@ -97,7 +97,7 @@ def _ReadMissingBlobHelp():
         return tag, msg
 
     my_data = pkg_resources.resource_string(__name__, 'missing-blob-help')
-    re_tag = re.compile('^([-a-z0-9]+):$')
+    re_tag = re.compile(r"^([-\.a-z0-9]+):$")
     result = {}
     tag = None
     msg = ''