MAINTAINERS: Update cxl maintainers

Fred has taken over the cxl maintenance I was doing. This updates the
MAINTAINERS file to reflect this.

It also removes a duplicate entry in the files covered and adds an entry
for the CXL PCI code in arch/powerpc.

Signed-off-by: Michael Neuling <[e-mail]>
Reviewed-by: Andrew Donnellan <[e-mail]>
Reviewed-by: Andrew Donnellan <[e-mail]>
Acked-by: Frederic Barrat <[e-mail]>
Signed-off-by: Michael Ellerman <[e-mail]>

MAINTAINERS

···
 
 CXL (IBM Coherent Accelerator Processor Interface CAPI) DRIVER
 M:	Ian Munsie <[e-mail]>
-M:	Michael Neuling <[e-mail]>
+M:	Frederic Barrat <[e-mail]>
 L:	[e-mail]
 S:	Supported
+F:	arch/powerpc/platforms/powernv/pci-cxl.c
 F:	drivers/misc/cxl/
 F:	include/misc/cxl*
 F:	include/uapi/misc/cxl.h
-F:	Documentation/powerpc/cxl.txt
 F:	Documentation/powerpc/cxl.txt
 F:	Documentation/ABI/testing/sysfs-class-cxl