Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/scripts/gdb/linux/Makefile b/scripts/gdb/linux/Makefile
index aba23be..1247550 100644
--- a/scripts/gdb/linux/Makefile
+++ b/scripts/gdb/linux/Makefile
@@ -1,24 +1,25 @@
 # SPDX-License-Identifier: GPL-2.0
-always := gdb-scripts
 
-SRCTREE := $(abspath $(srctree))
+ifdef building_out_of_srctree
 
-$(obj)/gdb-scripts:
-ifneq ($(KBUILD_SRC),)
-	$(Q)ln -fsn $(SRCTREE)/$(obj)/*.py $(objtree)/$(obj)
+symlinks := $(patsubst $(srctree)/$(src)/%,%,$(wildcard $(srctree)/$(src)/*.py))
+
+quiet_cmd_symlink = SYMLINK $@
+      cmd_symlink = ln -fsn $(patsubst $(obj)/%,$(abspath $(srctree))/$(src)/%,$@) $@
+
+extra-y += $(symlinks)
+$(addprefix $(obj)/, $(symlinks)): FORCE
+	$(call if_changed,symlink)
+
 endif
-	@:
 
 quiet_cmd_gen_constants_py = GEN     $@
       cmd_gen_constants_py = \
 	$(CPP) -E -x c -P $(c_flags) $< > $@ ;\
 	sed -i '1,/<!-- end-c-headers -->/d;' $@
 
-targets += constants.py
-$(obj)/constants.py: $(SRCTREE)/$(obj)/constants.py.in FORCE
+extra-y += constants.py
+$(obj)/constants.py: $(src)/constants.py.in FORCE
 	$(call if_changed_dep,gen_constants_py)
 
-build_constants_py: $(obj)/constants.py
-	@:
-
-clean-files := *.pyc *.pyo $(if $(KBUILD_SRC),*.py) $(obj)/constants.py
+clean-files := *.pyc *.pyo