[sonic-device-data] Fix config symlinks dereference (#2085)

('cp -H' -> 'cp -L')
'-L' does what we need in this case

From man cp
...
-H     follow command-line symbolic links in SOURCE
...
-L, --dereference
              always follow symbolic links in SOURCE

Signed-off-by: Stepan Blyschak <stepanb@mellanox.com>

src/sonic-device-data/Makefile

@@ -12,7 +12,7 @@ $(addprefix $(DEST)/, $(MAIN_TARGET)): $(DEST)/% :
 
 	# Create a new dir and copy all ONIE-platform-string-named dirs into it
 	mkdir ./device
-	cp -r -H ../../../device/*/* ./device/
+	cp -r -L ../../../device/*/* ./device/
 
 	# Build the package
 	dpkg-buildpackage -rfakeroot -b -us -uc