swupdate: add CONFIG_MTD only when platform supports NAND device

https://onedigi.atlassian.net/browse/DEL-7280

Signed-off-by: Mike Engel <Mike.Engel@digi.com>

meta-digi-dey/recipes-support/swupdate/swupdate/defconfig

@@ -24,7 +24,6 @@ CONFIG_SW_VERSIONS_FILE="/etc/sw-versions"
 #
 CONFIG_SOCKET_CTRL_PATH=""
 CONFIG_SOCKET_PROGRESS_PATH=""
-CONFIG_MTD=y
 # CONFIG_LUA is not set
 # CONFIG_FEATURE_SYSLOG is not set
 

meta-digi-dey/recipes-support/swupdate/swupdate/mtd.cfg

@@ -0,0 +1,2 @@
+# Add MTD support
+CONFIG_MTD=y

meta-digi-dey/recipes-support/swupdate/swupdate_2022.05.bbappend

@@ -9,6 +9,7 @@ SRC_URI += " \
     file://0001-Makefile-change-Makefile-to-build-swupdate-library-s.patch \
     file://0002-config-add-on-the-fly-build-configuration-variable.patch \
     ${@bb.utils.contains('DISTRO_FEATURES', 'systemd', 'file://systemd.cfg', '', d)} \
+    ${@bb.utils.contains('STORAGE_MEDIA', 'mtd', 'file://mtd.cfg', '', d)} \
 "
 
 do_configure:append() {