MAINTAINERS: switch to my OMP email for Renesas Ethernet drivers

I'm still going to continue looking after the Renesas Ethernet drivers and
device tree bindings. Now my new employer, Open Mobile Platform (OMP), will
pay for all my upstream work. Let's switch to my OMP email for the reviews.

Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Link: https://lore.kernel.org/r/9c212711-a0d7-39cd-7840-ff7abf938da1@omp.ru


Signed-off-by: Jakub Kicinski <kuba@kernel.org>