net: keystone_serdes: add keystone K2E SoC support

Keystone2 Edison SoC uses the same keystone SerDes driver.
This patch adds support for K2E SoCs.

Acked-by: Vitaly Andrianov <vitalya@ti.com>
Acked-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>
diff --git a/include/configs/k2e_evm.h b/include/configs/k2e_evm.h
index 3502d10..fd45d61 100644
--- a/include/configs/k2e_evm.h
+++ b/include/configs/k2e_evm.h
@@ -34,4 +34,7 @@
 /* NAND Configuration */
 #define CONFIG_SYS_NAND_PAGE_2K
 
+/* SerDes */
+#define CONFIG_TI_KEYSTONE_SERDES
+
 #endif /* __CONFIG_K2E_EVM_H */