net: wifi: shell: apply `struct option` as `static const`

This change marks the remaining instance of the `struct option` as
`static const`.

The rationale is that `struct option` is a read-only variable.
By using `static const`, we ensure immutability, leading to usage of only
the `.rodata` section and a reduction in the `.data` area.

Signed-off-by: Pisit Sawangvonganan <pisit@ndrsolution.com>
diff --git a/subsys/net/l2/wifi/wifi_shell.c b/subsys/net/l2/wifi/wifi_shell.c
index cea8e13..adf5b77 100644
--- a/subsys/net/l2/wifi/wifi_shell.c
+++ b/subsys/net/l2/wifi/wifi_shell.c
@@ -458,7 +458,7 @@
 	struct getopt_state *state;
 	int opt;
 	bool secure_connection = false;
-	static struct option long_options[] = {
+	static const struct option long_options[] = {
 		{"ssid", required_argument, 0, 's'},
 		{"passphrase", required_argument, 0, 'p'},
 		{"key-mgmt", required_argument, 0, 'k'},
@@ -1400,7 +1400,7 @@
 {
 	struct getopt_state *state;
 	int opt;
-	static struct option long_options[] = {
+	static const struct option long_options[] = {
 		{"max_inactivity", required_argument, 0, 'i'},
 		{"max_num_sta", required_argument, 0, 's'},
 		{"help", no_argument, 0, 'h'},
@@ -1970,7 +1970,7 @@
 	int opt;
 	int opt_index = 0;
 	struct getopt_state *state;
-	static struct option long_options[] = {
+	static const struct option long_options[] = {
 		{"peer", required_argument, 0, 'p'},
 		{"role", required_argument, 0, 'r'},
 		{"configurator", required_argument, 0, 'c'},
@@ -2018,7 +2018,7 @@
 	int opt;
 	int opt_index = 0;
 	struct getopt_state *state;
-	static struct option long_options[] = {
+	static const struct option long_options[] = {
 		{"own", required_argument, 0, 'i'},
 		{"freq", required_argument, 0, 'f'},
 		{0, 0, 0, 0}};
@@ -2054,7 +2054,7 @@
 	int opt;
 	int opt_index = 0;
 	struct getopt_state *state;
-	static struct option long_options[] = {
+	static const struct option long_options[] = {
 		{"role", required_argument, 0, 'r'},
 		{"freq", required_argument, 0, 'f'},
 		{0, 0, 0, 0}};
@@ -2090,7 +2090,7 @@
 	int opt;
 	int opt_index = 0;
 	struct getopt_state *state;
-	static struct option long_options[] = {
+	static const struct option long_options[] = {
 		{"type", required_argument, 0, 't'},
 		{"opclass", required_argument, 0, 'o'},
 		{"channel", required_argument, 0, 'h'},
@@ -2152,7 +2152,7 @@
 	int opt;
 	int opt_index = 0;
 	struct getopt_state *state;
-	static struct option long_options[] = {
+	static const struct option long_options[] = {
 		{"configurator", required_argument, 0, 'c'},
 		{"mode", required_argument, 0, 'm'},
 		{"ssid", required_argument, 0, 's'},