MAINTAINERS: Add missing documentation references to PCI Endpoint Subsystem

Adds documentation reference created by Kishon Abraham to the
MAINTAINERS list relative with the PCI endpoint subsystem section.

Link: https://lore.kernel.org/r/4fa78c7a24e8f8ec3206e1e8960dc18f505c9e29.1597695880.git.gustavo.pimentel@synopsys.comSigned-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

MAINTAINERS

@@ -13480,6 +13480,8 @@ M:	Kishon Vijay Abraham I <kishon@ti.com>
 M:	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
 L:	linux-pci@vger.kernel.org
 S:	Supported
+F:	Documentation/PCI/endpoint/*
+F:	Documentation/misc-devices/pci-endpoint-test.rst
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/kishon/pci-endpoint.git
 F:	drivers/misc/pci_endpoint_test.c
 F:	drivers/pci/endpoint/