[][Cheetah][modify min_free_kbytes to more suitable for projects with less memory]

Change min_free_kbytes to more suitable for Cheetah
1. 256M: change to 4MiB
2. 128M: change to 2MiB


Change-Id: I1b71a81c1ef16078e4cf1e9f0f353d67adf10161
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/5633593
diff --git a/target/linux/mediatek/mt7981/base-files/etc/sysctl.d/99-min-free-kbytes.conf b/target/linux/mediatek/mt7981/base-files/etc/sysctl.d/99-min-free-kbytes.conf
new file mode 100644
index 0000000..c64b8b5
--- /dev/null
+++ b/target/linux/mediatek/mt7981/base-files/etc/sysctl.d/99-min-free-kbytes.conf
@@ -0,0 +1,5 @@
+# Do not edit, changes to this file will be lost on upgrades
+# # /etc/sysctl.conf can be used to customize sysctl settings