net: macb: phytium-gem: donot convert the enum constant to a boolean

Fix follow error with clang-19:

drivers/net/ethernet/cadence/macb_main.c:724:71: error: converting the enum constant to a boolean [-Werror,-Wint-in-bool-context]
  724 |         if (macb_is_gem(bp) && (state->interface == PHY_INTERFACE_MODE_SGMII ||
      |                                                                              ^
1 error generated.

Signed-off-by: WangYuli <wangyuli@uniontech.com>

drivers/net/ethernet/cadence/macb_main.c

@@ -683,7 +683,8 @@ static void macb_mac_config(struct phylink_config *config, unsigned int mode,
 	 * Must be written after PCSSEL is set in NCFGR,
 	 * otherwise writes will not take effect.
 	 */
-	if (macb_is_gem(bp) && state->interface == PHY_INTERFACE_MODE_SGMII) {
+	if (macb_is_gem(bp) && (state->interface == PHY_INTERFACE_MODE_SGMII ||
+				state->interface == PHY_INTERFACE_MODE_2500BASEX)) {
 		u32 pcsctrl, old_pcsctrl;
 
 		old_pcsctrl = gem_readl(bp, PCSCNTRL);