drivers: ethernet: stm32: Set API V2 as default

Set STM32CubeHAL ethernet version in use as V2 by default, on series
supporting it (H7, F7, F4). Not yet available on F2 series.

Add a choice symbol to explicit V1 version as deprecated.

Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>