[][Add initial mtk feed for OpenWRT v21.02]

[Description]
Add initial mtk feed for OpenWRT v21.02

[Release-log]
N/A

Change-Id: I8051c6ba87f1ccf26c02fdd88a17d66f63c0b101
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/4495320
diff --git a/target/linux/mediatek/patches-5.4/0504-macsec-revert-async-support.patch b/target/linux/mediatek/patches-5.4/0504-macsec-revert-async-support.patch
new file mode 100644
index 0000000..d52db50
--- /dev/null
+++ b/target/linux/mediatek/patches-5.4/0504-macsec-revert-async-support.patch
@@ -0,0 +1,12 @@
+--- a/drivers/net/macsec.c
++++ b/drivers/net/macsec.c
+@@ -1309,8 +1309,7 @@
+ 	struct crypto_aead *tfm;
+ 	int ret;
+ 
+-	/* Pick a sync gcm(aes) cipher to ensure order is preserved. */
+-	tfm = crypto_alloc_aead("gcm(aes)", 0, CRYPTO_ALG_ASYNC);
++	tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
+ 
+ 	if (IS_ERR(tfm))
+ 		return tfm;