MAINTAINERS: add an entry for kfifo

Kfifo has been written by Stefani Seibold and she's implicitly expected
to Ack any changes to it.  She's not however officially listed as kfifo
maintainer which leads to delays in patch review.  This patch proposes
to add an explitic entry for kfifo to MAINTAINERS file.

[akpm@linux-foundation.org: alphasort F: entries, per Joe]
[akpm@linux-foundation.org: remove colon, per Bartosz]
Link: http://lkml.kernel.org/r/20200124174533.21815-1-brgl@bgdev.pl
Link: http://lkml.kernel.org/r/20200413104250.26683-1-brgl@bgdev.pl


Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>