net: stmmac: dwmac-qcom-ethqos: use devm_stmmac_pltfr_probe()

Use the devres variant of stmmac_pltfr_probe() and finally drop the
remove() callback entirely.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://lore.kernel.org/r/20230623100417.93592-12-brgl@bgdev.pl


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