net: phy: micrel: Fix detection of ksz87xx switch

The logic for discerning between KSZ8051 and KSZ87XX PHYs is incorrect
such that the that KSZ87XX switch is not identified correctly.

ksz8051_ksz8795_match_phy_device() uses the parameter ksz_phy_id
to discriminate whether it was called from ksz8051_match_phy_device()
or from ksz8795_match_phy_device() but since PHY_ID_KSZ87XX is the
same value as PHY_ID_KSZ8051, this doesn't work.

Instead use a bool to discriminate the caller.

Without this patch, the KSZ8795 switch port identifies as:

ksz8795-switch spi3.1 ade1 (uninitialized): PHY [dsa-0.1:03] driver [Generic PHY]

With the patch, it identifies correctly:

ksz8795-switch spi3.1 ade1 (uninitialized): PHY [dsa-0.1:03] driver [Micrel KSZ87XX Switch]

Fixes: 8b95599c ("net: phy: micrel: Discern KSZ8051 and KSZ8795 PHYs")
Signed-off-by: Steve Bennett <steveb@workware.net.au>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>