net: dsa: lantiq_gswip: deduplicate dsa_switch_ops

net: dsa: lantiq_gswip: deduplicate dsa_switch_ops

The two instances of struct dsa_switch_ops differ only by their
.phylink_get_caps op. Instead of having two instances of dsa_switch_ops,
rather just have a pointer to the phylink_get_caps function in
struct gswip_hw_info.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://patch.msgid.link/03d72eceeb3faecdbe03ce58aab40861cf6b77c1.1755878232.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>