MAINTAINERS: Add James as MIPS co-maintainer

MAINTAINERS: Add James as MIPS co-maintainer

I've been taking on some co-maintainer duties already, so lets make it
official in the MAINTAINERS file.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: James Hogan <[email protected]>
Acked-by: Paul Burton <[email protected]>
Acked-by: Aaro Koskinen <[email protected]>
Acked-by: David Daney <[email protected]>
Acked-by: Florian Fainelli <[email protected]>
Acked-by: Matt Redfearn <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: John Crispin <[email protected]>
Cc: [email protected]
Patchwork: https://patchwork.linux-mips.org/patch/18211/