mailbox: Introduce framework for mailbox

Introduce common framework for client/protocol drivers and
controller drivers of Inter-Processor-Communication (IPC).

Client driver developers should have a look at
 include/linux/mailbox_client.h to understand the part of
the API exposed to client drivers.
Similarly controller driver developers should have a look
at include/linux/mailbox_controller.h

Reviewed-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index a12edf2..c5f7c85 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5740,6 +5740,14 @@
 F:	drivers/net/macvlan.c
 F:	include/linux/if_macvlan.h
 
+MAILBOX API
+M:	Jassi Brar <jassisinghbrar@gmail.com>
+L:	linux-kernel@vger.kernel.org
+S:	Maintained
+F:	drivers/mailbox/
+F:	include/linux/mailbox_client.h
+F:	include/linux/mailbox_controller.h
+
 MAN-PAGES: MANUAL PAGES FOR LINUX -- Sections 2, 3, 4, 5, and 7
 M:	Michael Kerrisk <mtk.manpages@gmail.com>
 W:	http://www.kernel.org/doc/man-pages