kernel: generic: fix perf build breakage on 4.19

Drop 211-host_tools_portability.patch which is breaking perf build on
4.19 kernels by removing the include directory from the host's CFLAGS
leading to the following build breakage:

 pmu-events/jevents.c:48:10: fatal error: linux/list.h: No such file or directory
  #include <linux/list.h>
           ^~~~~~~~~~~~~~

Signed-off-by: Petr Štetiar <ynezz@true.cz>

target/linux/generic/hack-4.19/211-host_tools_portability.patch

@@ -1,40 +0,0 @@
-From 7f698012384ccb1ed10cc758acfd085096fdb307 Mon Sep 17 00:00:00 2001
-From: Felix Fietkau <nbd@nbd.name>
-Date: Fri, 7 Jul 2017 17:02:03 +0200
-Subject: kernel: fix linux 4.9 host tools portability issues
-
-Signed-off-by: Felix Fietkau <nbd@nbd.name>
----
- tools/build/Build.include       | 2 +-
- tools/perf/pmu-events/jevents.c | 1 +
- tools/perf/pmu-events/json.c    | 1 -
- 3 files changed, 2 insertions(+), 2 deletions(-)
-
---- a/tools/build/Build.include
-+++ b/tools/build/Build.include
-@@ -98,4 +98,4 @@ cxx_flags = -Wp,-MD,$(depfile) -Wp,-MT,$
- ###
- ## HOSTCC C flags
- 
--host_c_flags = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(KBUILD_HOSTCFLAGS) -D"BUILD_STR(s)=\#s" $(HOSTCFLAGS_$(basetarget).o) $(HOSTCFLAGS_$(obj))
-+host_c_flags = -MD -MF $(depfile) -MT $@ $(CHOSTFLAGS) -D"BUILD_STR(s)=\#s" $(CHOSTFLAGS_$(basetarget).o) $(CHOSTFLAGS_$(obj))
---- a/tools/perf/pmu-events/jevents.c
-+++ b/tools/perf/pmu-events/jevents.c
-@@ -35,6 +35,7 @@
- #include <stdlib.h>
- #include <errno.h>
- #include <string.h>
-+#include <strings.h>
- #include <ctype.h>
- #include <unistd.h>
- #include <stdarg.h>
---- a/tools/perf/pmu-events/json.c
-+++ b/tools/perf/pmu-events/json.c
-@@ -38,7 +38,6 @@
- #include <unistd.h>
- #include "jsmn.h"
- #include "json.h"
--#include <linux/kernel.h>
- 
- 
- static char *mapfile(const char *fn, size_t *size)