MAINTAINERS: Add Gustavo Pimentel as DesignWare PCI maintainer

Currently I am managing the Synopsys drivers & tools team (full-time) and
so I am passing the pcie-designware maintenance to Gustavo.

Signed-off-by: Joao Pinto <jpinto@synopsys.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
CC: Jingoo Han <jingoohan1@gmail.com>

MAINTAINERS

@@ -11167,7 +11167,7 @@ F:	drivers/pci/controller/dwc/pci-exynos.c
 
 PCI DRIVER FOR SYNOPSYS DESIGNWARE
 M:	Jingoo Han <jingoohan1@gmail.com>
-M:	Joao Pinto <Joao.Pinto@synopsys.com>
+M:	Gustavo Pimentel <gustavo.pimentel@synopsys.com>
 L:	linux-pci@vger.kernel.org
 S:	Maintained
 F:	Documentation/devicetree/bindings/pci/designware-pcie.txt