GCC 10+ defaults to `-fno-common`, breaking build of dtc binary.

Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>

diff --git a/scripts/dtc/Makefile b/scripts/dtc/Makefile
index b5a5b1c..5c2f139 100644
--- a/scripts/dtc/Makefile
+++ b/scripts/dtc/Makefile
@@ -11,6 +11,9 @@ dtc-objs	+= dtc-lexer.lex.o dtc-parser.tab.o
 # Source files need to get at the userspace version of libfdt_env.h to compile
 HOST_EXTRACFLAGS := -I $(srctree)/$(src)/libfdt
 
+# Combine `yylloc` declarations from dtc-lexer.lex.o and dtc-parser.tab.o
+HOST_EXTRACFLAGS += -fcommon
+
 ifeq ($(shell pkg-config --exists yaml-0.1 2>/dev/null && echo yes),)
 ifneq ($(CHECK_DTBS),)
 $(error dtc needs libyaml for DT schema validation support. \