net: phy: smsc: add proper reset flags for LAN8710A

According to the LAN8710A datasheet (Rev. B, section 3.8.5.1), a hardware
reset is required after power-on, and the reference clock (REF_CLK) must be
established before asserting reset.

Signed-off-by: Buday Csaba <buday.csaba@prolan.hu>
Cc: Csókás Bence <csokas.bence@prolan.hu>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20250728152916.46249-2-csokas.bence@prolan.hu


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