MAINTAINERS: Add Krzysztof as PCI host/endpoint controllers reviewer

Krzysztof has been carrying out PCI patches review for a long time and
he has been instrumental in driving PCI host/endpoint controller drivers
improvements.

Make his role official.

Link: https://lore.kernel.org/r/20210511150003.1592-1-lorenzo.pieralisi@arm.com
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Krzysztof Wilczyński <kw@linux.com>

Author: Lorenzo Pieralisi

MAINTAINERS

@@ -14110,6 +14110,7 @@ F:	drivers/pci/controller/pci-v3-semi.c
 PCI ENDPOINT SUBSYSTEM
 M:	Kishon Vijay Abraham I <kishon@ti.com>
 M:	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+R:	Krzysztof Wilczyński <kw@linux.com>
 L:	linux-pci@vger.kernel.org
 S:	Supported
 F:	Documentation/PCI/endpoint/*
@@ -14158,6 +14159,7 @@ F:	drivers/pci/controller/pci-xgene-msi.c
 PCI NATIVE HOST BRIDGE AND ENDPOINT DRIVERS
 M:	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
 R:	Rob Herring <robh@kernel.org>
+R:	Krzysztof Wilczyński <kw@linux.com>
 L:	linux-pci@vger.kernel.org
 S:	Supported
 Q:	http://patchwork.ozlabs.org/project/linux-pci/list/