net: phy: aquantia: merge aqr113c_fill_interface_modes() into aqr107_fill_interface_m...

net: phy: aquantia: merge aqr113c_fill_interface_modes() into aqr107_fill_interface_modes()

I'm unsure whether intentionate or not, but I think the (partially
observed) naming convention in this driver is that function prefixes
denote the earliest generation when a feature is available. In case of
aqr107_fill_interface_modes(), that means that the GLOBAL_CFG registers
are a Gen2 feature. Supporting evidence: the AQR105, a Gen1 PHY, does
not have these registers, thus the function is not named aqr105_*.

Based on this inferred naming scheme, I am proposing a refinement of
commit a7f3abcf6357 ("net: phy: aquantia: only poll GLOBAL_CFG regs on
aqr113, aqr113c and aqr115c") which introduced aqr113c_fill_interface_modes(),
suggesting this may be a Gen4 PHY feature.

The long-term goal is for aqr107_config_init() to tail-call
aqr107_fill_interface_modes(), such that the latter function is also
called by AQR107 itself, and many other PHY drivers. Currently it can't,
because aqr113c_config_init() calls aqr107_config_init() and then
aqr113c_fill_interface_modes(). So this would lead to a duplicate call
to aqr107_fill_interface_modes() for AQR113C.

Centralize the reading of GLOBAL_CFG registers in the AQR107 method, and
create a boolean, set to true by AQR113C, which tests whether waiting
for a non-zero value in the GLOBAL_CFG_100M register is necessary.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20250821152022.1065237-3-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>