MAINTAINERS: Remove linux-mips.org references

The linux-mips.org site has gone down and no replacement is available at
the moment.  Remove/update references in MAINTAINERS accordingly.  There
are a bunch of Kconfig references still present; keep them around for a
possible future update or for people to refer to via archive.org.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Author: maciej-w-rozycki

MAINTAINERS

@@ -6299,7 +6299,6 @@ DECSTATION PLATFORM SUPPORT
 M:	"Maciej W. Rozycki" <macro@orcam.me.uk>
 L:	linux-mips@vger.kernel.org
 S:	Maintained
-W:	http://www.linux-mips.org/wiki/DECstation
 F:	arch/mips/dec/
 F:	arch/mips/include/asm/dec/
 F:	arch/mips/include/asm/mach-dec/
@@ -15424,7 +15423,6 @@ MIPS
 M:	Thomas Bogendoerfer <tsbogend@alpha.franken.de>
 L:	linux-mips@vger.kernel.org
 S:	Maintained
-W:	http://www.linux-mips.org/
 Q:	https://patchwork.kernel.org/project/linux-mips/list/
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux.git
 F:	Documentation/devicetree/bindings/mips/
@@ -23493,7 +23491,7 @@ TURBOCHANNEL SUBSYSTEM
 M:	"Maciej W. Rozycki" <macro@orcam.me.uk>
 L:	linux-mips@vger.kernel.org
 S:	Maintained
-Q:	http://patchwork.linux-mips.org/project/linux-mips/list/
+Q:	https://patchwork.kernel.org/project/linux-mips/list/
 F:	drivers/tc/
 F:	include/linux/tc.h