MAINTAINERS: Update EEH details and maintainership

[Michael Ellerman]

On Wed, 2016-17-02 at 06:06:04 UTC, Russell Currey wrote:
> Enhanced Error Handling could mean anything in the context of the entire
> kernel, so change the name to reference that it is both for PCI and
> powerpc.
> 
> EEH covers a bit more than the previously listed files, so add the headers
> and platform-specific code to the EEH maintained section.
> 
> In addition, I am taking over the maintainership.
> 
> Signed-off-by: Russell Currey <ruscur at russell.cc>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/78c1cffdab7e5fc316be7d6a07

cheers