net: ti: am65-cpsw-nuss: Use syscon_regmap_lookup_by_phandle_args

net: ti: am65-cpsw-nuss: Use syscon_regmap_lookup_by_phandle_args

Use syscon_regmap_lookup_by_phandle_args() which is a wrapper over
syscon_regmap_lookup_by_phandle() combined with getting the syscon
argument.  Except simpler code this annotates within one line that given
phandle has arguments, so grepping for code would be easier.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20250112-syscon-phandle-args-net-v1-2-3423889935f7@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>