net: lan78xx: fix accessing the LAN7800's internal phy specific registers from the MAC driver

[ Upstream commit e57cf363 ]

Move the LAN7800 internal phy (phy ID  0x0007c132) specific register
accesses to the phy driver (microchip.c).

Fix the error reported by Enguerrand de Ribaucourt in December 2022,
"Some operations during the cable switch workaround modify the register
LAN88XX_INT_MASK of the PHY. However, this register is specific to the
LAN8835 PHY. For instance, if a DP8322I PHY is connected to the LAN7801,
that register (0x19), corresponds to the LED and MAC address
configuration, resulting in unapropriate behavior."

I did not test with the DP8322I PHY, but I tested with an EVB-LAN7800
with the internal PHY.

Fixes: 14437e3f

 ("lan78xx: workaround of forced 100 Full/Half duplex mode error")
Signed-off-by: Yuiko Oshino <yuiko.oshino@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20230301154307.30438-1-yuiko.oshino@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>