EDAC/highbank: Handover Calxeda Highbank maintenance to Andre Przywara

I do not have hardware anymore, nor there is ongoing development. So
handover maintenance to Andre who already maintains the last remainings
of Calxeda.

Signed-off-by: Robert Richter <[e-mail]>
Signed-off-by: Borislav Petkov <[e-mail]>
Acked-by: Andre Przywara <[e-mail]>
Link: https://lkml.kernel.org/r/[e-mail]

MAINTAINERS

···
 F:	drivers/edac/bluefield_edac.c
 
 EDAC-CALXEDA
-M:	Robert Richter <[e-mail]>
+M:	Andre Przywara <[e-mail]>
 L:	[e-mail]
 S:	Maintained
 F:	drivers/edac/highbank*