linux-dey: fix apply of kernel configuration fragments

- Add the '-m' parameter. Without it, the script doesn't
  generate the output merged configuration file, and the
  fragments are not applied.
- Fix the if condition. The '*.cfg' expands to a list of
  files, but the '-f' only admits one parameter. Use instead
  the Python find_cfgs() function.

Signed-off-by: Hector Palacios <hector.palacios@digi.com>

meta-digi-arm/recipes-kernel/linux/linux-dey_5.4.bb

@@ -93,8 +93,8 @@ do_configure_append() {
 	# Only accept fragments ending in .cfg. If the fragments contain
 	# something other than kernel configs, it will be filtered out
 	# automatically.
-	if [ -f ${WORKDIR}/*.cfg ]; then
-		${S}/scripts/kconfig/merge_config.sh -O ${B} ${B}/.config ${WORKDIR}/*.cfg
+	if [ -n "${@' '.join(find_cfgs(d))}" ]; then
+		${S}/scripts/kconfig/merge_config.sh -m -O ${B} ${B}/.config ${@" ".join(find_cfgs(d))}
 	fi
 }