dts: bindings: Add RGMII mode definition to NXP ENET bindings

Add RGMII mode definition to be used in bindings related to NXP ENET_1G IP.

Fixes: #66348

Signed-off-by: Stanislav Poboril <[email protected]>

Author: stanislav-poboril

include/zephyr/dt-bindings/ethernet/nxp_enet.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2023 NXP
+ * Copyright 2023-2024 NXP
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -9,6 +9,7 @@
 
 #define NXP_ENET_MII_MODE	0
 #define NXP_ENET_RMII_MODE	1
+#define NXP_ENET_RGMII_MODE	2
 #define NXP_ENET_INVALID_MII_MODE 100
 
 #endif /* ZEPHYR_INCLUDE_DT_BINDINGS_NXP_ENET_H_ */