net: ethernet: cortina: Locking fixes

This fixes a probably long standing problem in the Cortina
Gemini ethernet driver: there are some paths in the code
where the IRQ registers are written without taking the proper
locks.

Fixes: 4d5ae32f ("net: ethernet: Add a driver for Gemini gigabit ethernet")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240509-gemini-ethernet-locking-v1-1-afd00a528b95@linaro.org


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