[Fix firewall work abnormal issue]

[Description]
Fix firewall work abnormal issue
1. add lack kernel config in iptables.cfg
2. reorder kernel config merge order
origin: defconfig->rdkb_cfg->mt7986.cfg
now: defconfig -> mt7986.cfg -> rdkb_cfg

[Release-log]

diff --git a/recipes-kernel/linux/linux-mediatek_5.4.bb b/recipes-kernel/linux/linux-mediatek_5.4.bb
index 54e1a92..4877f37 100644
--- a/recipes-kernel/linux/linux-mediatek_5.4.bb
+++ b/recipes-kernel/linux/linux-mediatek_5.4.bb
@@ -22,13 +22,6 @@
     file://001-rdkb-eth-mtk-change-ifname-for.patch;apply=no \
     file://002-rdkb-mtd-ubi-relayout.patch;apply=no \
     "
-SRC_URI += " \
-    file://rdkb_cfg/iptables.cfg \
-    file://rdkb_cfg/turris_rdkb.cfg \
-    file://rdkb_cfg/openvswitch.cfg \
-    file://rdkb_cfg/mac80211.cfg \
-    file://rdkb_cfg/prplmesh.cfg \
-"
 
 SRC_URI_append_mt7986 += " \
     file://mediatek/mt7986.cfg \
@@ -38,6 +31,13 @@
     file://mediatek/patches-32bit-5.4/401-pinctrl-add-mt7986-driver-32bit.patch \
     file://mediatek/patches-32bit-5.4/999-add_armv7_support_for_panther.patch \
 "
+SRC_URI_append += " \
+    file://rdkb_cfg/iptables.cfg \
+    file://rdkb_cfg/turris_rdkb.cfg \
+    file://rdkb_cfg/openvswitch.cfg \
+    file://rdkb_cfg/mac80211.cfg \
+    file://rdkb_cfg/prplmesh.cfg \
+"
 require ${PN}-${PV}/generic/backport-5.4/backport-5.4.inc
 
 require ${PN}-${PV}/generic/pending-5.4/pending-5.4.inc