MAINTAINERS: Update page pool entry

Add some file F: matches that is related to page_pool.

Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/r/160613894639.2826716.14635284017814375894.stgit@firesoul
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: netoptimizer

MAINTAINERS

@@ -13161,7 +13161,9 @@ M:	Jesper Dangaard Brouer <hawk@kernel.org>
 M:	Ilias Apalodimas <ilias.apalodimas@linaro.org>
 L:	netdev@vger.kernel.org
 S:	Supported
+F:	Documentation/networking/page_pool.rst
 F:	include/net/page_pool.h
+F:	include/trace/events/page_pool.h
 F:	net/core/page_pool.c
 
 PANASONIC LAPTOP ACPI EXTRAS DRIVER