MAINTAINERS: Remove myself

I no longer have any faith left in the kernel development process or
community management approach.

Apple/ARM platform development will continue downstream. If I feel like
sending some patches upstream in the future myself for whatever subtree
I may, or I may not. Anyone who feels like fighting the upstreaming
fight themselves is welcome to do so.

Signed-off-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>