kernel: bump 4.9 to 4.9.171

Refreshed all patches.

Altered patches:
- 150-bridge_allow_receiption_on_disabled_port.patch
- 201-extra_optimization.patch

Compile-tested on: ar71xx
Runtime-tested on: ar71xx

Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>

target/linux/generic/hack-4.9/207-disable-modorder.patch

@@ -15,7 +15,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 
 --- a/Makefile
 +++ b/Makefile
-@@ -1227,7 +1227,6 @@ all: modules
+@@ -1226,7 +1226,6 @@ all: modules
  
  PHONY += modules
  modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
@@ -23,7 +23,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  	@$(kecho) '  Building modules, stage 2.';
  	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
  	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.fwinst obj=firmware __fw_modbuild
-@@ -1257,7 +1256,6 @@ _modinst_:
+@@ -1256,7 +1255,6 @@ _modinst_:
  		rm -f $(MODLIB)/build ; \
  		ln -s $(CURDIR) $(MODLIB)/build ; \
  	fi