zephyr: kconfig: Make saving encrypt TLVs depending on encryption

Prevents enabling the option to save encrypted TLVs if encryption
support is not enabled, as it is required to make use of this
functionality.

Signed-off-by: Jamie McCrae <[email protected]>

Author: nordicjm

boot/zephyr/Kconfig

@@ -306,6 +306,7 @@ config BOOT_BOOTSTRAP
 config BOOT_SWAP_SAVE_ENCTLV
 	bool "Save encrypted key TLVs instead of plaintext keys in swap metadata"
 	default n
+	depends on BOOT_ENCRYPT_IMAGE
 	help
 	  If y, instead of saving the encrypted image keys in plaintext in the
 	  swap resume metadata, save the encrypted image TLVs. This should be used