wifi: rtw89: declare support bands with const

They are just default declarations and we won't modify them directly.
Instead, we actually do moification on their memdup now. So, they
should be declared with const.
Signed-off-by: Zong-Zhe Yang <kevin_yang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20221020052702.33988-1-pkshih@realtek.com

drivers/net/wireless/realtek/rtw89/core.c

@@ -171,7 +171,7 @@ bool rtw89_ra_report_to_bitrate(struct rtw89_dev *rtwdev, u8 rpt_rate, u16 *bitr
 	return true;
 }
 
-static struct ieee80211_supported_band rtw89_sband_2ghz = {
+static const struct ieee80211_supported_band rtw89_sband_2ghz = {
 	.band		= NL80211_BAND_2GHZ,
 	.channels	= rtw89_channels_2ghz,
 	.n_channels	= ARRAY_SIZE(rtw89_channels_2ghz),
@@ -181,7 +181,7 @@ static struct ieee80211_supported_band rtw89_sband_2ghz = {
 	.vht_cap	= {0},
 };
 
-static struct ieee80211_supported_band rtw89_sband_5ghz = {
+static const struct ieee80211_supported_band rtw89_sband_5ghz = {
 	.band		= NL80211_BAND_5GHZ,
 	.channels	= rtw89_channels_5ghz,
 	.n_channels	= ARRAY_SIZE(rtw89_channels_5ghz),
@@ -193,7 +193,7 @@ static struct ieee80211_supported_band rtw89_sband_5ghz = {
 	.vht_cap	= {0},
 };
 
-static struct ieee80211_supported_band rtw89_sband_6ghz = {
+static const struct ieee80211_supported_band rtw89_sband_6ghz = {
 	.band		= NL80211_BAND_6GHZ,
 	.channels	= rtw89_channels_6ghz,
 	.n_channels	= ARRAY_SIZE(rtw89_channels_6ghz),