net: ethernet: oa_tc6: implement error interrupts unmasking

net: ethernet: oa_tc6: implement error interrupts unmasking

This will unmask the following error interrupts from the MAC-PHY.
  tx protocol error
  rx buffer overflow error
  loss of framing error
  header error
The MAC-PHY will signal an error by setting the EXST bit in the receive
data footer which will then allow the host to read the STATUS0 register
to find the source of the error.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Parthiban Veerasooran <Parthiban.Veerasooran@microchip.com>
Link: https://patch.msgid.link/20240909082514.262942-6-Parthiban.Veerasooran@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>