MAINTAINERS: update Andreas Hindborg's email address

Move away from corporate infrastructure for upstream work. Also update
mailmap.

Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20240903200956.68231-1-a.hindborg@kernel.org


[ Reworded title slightly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>