add 3rd party/custom patches

3rd patchs (in alphabetical order):
- bbr3
- ntsync5
- openwrt
- pf-kernel
- xanmod
- zen

no configuration changes for now

debian/patches/patchset-zen/sauce/0011-ZEN-INTERACTIVE-Base-config-item.patch

@@ -0,0 +1,24 @@
+From 032775267df11a87616d2ec7f09c0b1b12da5da7 Mon Sep 17 00:00:00 2001
+From: "Jan Alexander Steffens (heftig)" <jan.steffens@gmail.com>
+Date: Mon, 27 Jan 2020 18:10:06 +0100
+Subject: ZEN: INTERACTIVE: Base config item
+
+---
+ init/Kconfig | 6 ++++++
+ 1 file changed, 6 insertions(+)
+
+--- a/init/Kconfig
++++ b/init/Kconfig
+@@ -134,6 +134,12 @@ config THREAD_INFO_IN_TASK
+ 
+ menu "General setup"
+ 
++config ZEN_INTERACTIVE
++	bool "Tune kernel for interactivity"
++	default y
++	help
++	  Tunes the kernel for responsiveness at the cost of throughput and power usage.
++
+ config BROKEN
+ 	bool
+