tools/genboardscfg.py: pick up also commented maitainers

We are still keeping invalid email addressed in MAINTAINERS
because they carry information.

The problem is that scripts/get_maintainer.pl adds emails in the
"M:" field including invalid ones.

We want to comment out invalid email addresses in MAINTAINERS
to prevent scripts/get_maintainer.pl from picking them up.
On the other hand, we want to collect them for boards.cfg
to know the last known maintainer of each board.

This commit adjusts tools/genboardscfg.py to parse also
the commented "M:" fields, which is useful for the next commit.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>

tools/genboardscfg.py

@@ -328,6 +328,9 @@ class MaintainersDatabase:
         maintainers = []
         status = '-'
         for line in open(file):
+            # Check also commented maintainers
+            if line[:3] == '#M:':
+                line = line[1:]
             tag, rest = line[:2], line[2:].strip()
             if tag == 'M:':
                 maintainers.append(rest)