env: Fix network support when CONFIG_NET_LWIP is set

When lwIP (CONFIG_NET_LWIP) is used instead of legacy stack (CONFIG_NET),
environment flags support associated with network was not built: restore
support of "i" and "m" environment flags.

Signed-off-by: Benjamin ROBIN <dev@benjarobin.fr>
Acked-by: Jerome Forissier <jerome.forissier@linaro.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/env/flags.c b/env/flags.c
index 233fd46..f734fda 100644
--- a/env/flags.c
+++ b/env/flags.c
@@ -22,7 +22,7 @@
 #include <env_internal.h>
 #endif
 
-#ifdef CONFIG_NET
+#if CONFIG_IS_ENABLED(NET) || CONFIG_IS_ENABLED(NET_LWIP)
 #define ENV_FLAGS_NET_VARTYPE_REPS "im"
 #else
 #define ENV_FLAGS_NET_VARTYPE_REPS ""
@@ -57,7 +57,7 @@
 	"decimal",
 	"hexadecimal",
 	"boolean",
-#ifdef CONFIG_NET
+#if CONFIG_IS_ENABLED(NET) || CONFIG_IS_ENABLED(NET_LWIP)
 	"IP address",
 	"MAC address",
 #endif
@@ -211,7 +211,7 @@
 		*end = value;
 }
 
-#ifdef CONFIG_NET
+#if CONFIG_IS_ENABLED(NET) || CONFIG_IS_ENABLED(NET_LWIP)
 int eth_validate_ethaddr_str(const char *addr)
 {
 	const char *end;
@@ -244,7 +244,7 @@
 	enum env_flags_vartype type)
 {
 	const char *end;
-#ifdef CONFIG_NET
+#if CONFIG_IS_ENABLED(NET) || CONFIG_IS_ENABLED(NET_LWIP)
 	const char *cur;
 	int i;
 #endif
@@ -273,7 +273,7 @@
 		if (value[1] != '\0')
 			return -1;
 		break;
-#ifdef CONFIG_NET
+#if CONFIG_IS_ENABLED(NET) || CONFIG_IS_ENABLED(NET_LWIP)
 	case env_flags_vartype_ipaddr:
 		cur = value;
 		for (i = 0; i < 4; i++) {