MAINTAINERS: Drop Gustavo Pimentel as PCI DWC Maintainer

Gustavo Pimentel seems to have left Synopsys, so his email is bouncing.
And there is no indication from him expressing willingless to continue
contributing to the driver.

Drop him from the MAINTAINERS entry and add a CREDITS entry.

Link: https://lore.kernel.org/r/20240326085130.12487-1-manivannan.sadhasivam@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
[bhelgaas: add CREDITS entry]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Author: Mani-Sadhasivam

CREDITS

@@ -3146,6 +3146,10 @@ S: Triftstra=DFe 55
 S: 13353 Berlin
 S: Germany
 
+N: Gustavo Pimental
+E: gustavo.pimentel@synopsys.com
+D: PCI driver for Synopsys DesignWare
+
 N: Emanuel Pirker
 E: epirker@edu.uni-klu.ac.at
 D: AIC5800 IEEE 1394, RAW I/O on 1394

MAINTAINERS

@@ -16966,7 +16966,6 @@ F:	drivers/pci/controller/dwc/pci-exynos.c
 
 PCI DRIVER FOR SYNOPSYS DESIGNWARE
 M:	Jingoo Han <jingoohan1@gmail.com>
-M:	Gustavo Pimentel <gustavo.pimentel@synopsys.com>
 M:	Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
 L:	linux-pci@vger.kernel.org
 S:	Maintained