sfc: Rename 'xfp' file and functions to reflect reality

The 'XFP' driver is really a driver for the QT2022C2 and QT2025C PHYs,
covering both more and less than XFP.  Rename its functions and
constants to reflect reality and to reduce namespace pollution when
sfc is a built-in driver.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/sfc/falcon.c b/drivers/net/sfc/falcon.c
index d9ce21e..8776432 100644
--- a/drivers/net/sfc/falcon.c
+++ b/drivers/net/sfc/falcon.c
@@ -2239,7 +2239,7 @@
 		break;
 	case PHY_TYPE_QT2022C2:
 	case PHY_TYPE_QT2025C:
-		efx->phy_op = &falcon_xfp_phy_ops;
+		efx->phy_op = &falcon_qt202x_phy_ops;
 		break;
 	default:
 		EFX_ERR(efx, "Unknown PHY type %d\n",