zephyr: serial_recovery: Use Zephyr manifest zcbor files

Switches from using the zcbor files in-tree to using the ones that
are part of the zephyr manifest, this prevents using old and
potentially buggy versions of the zcbor library.

Signed-off-by: Jamie McCrae <jamie.mccrae@nordicsemi.no>
diff --git a/boot/zephyr/Kconfig.serial_recovery b/boot/zephyr/Kconfig.serial_recovery
index 92d0da0..aba2d58 100644
--- a/boot/zephyr/Kconfig.serial_recovery
+++ b/boot/zephyr/Kconfig.serial_recovery
@@ -14,6 +14,7 @@
 	select UART_INTERRUPT_DRIVEN
 	select BASE64
 	select CRC
+	select ZCBOR
 	help
 	  If y, enables a serial-port based update mode. This allows
 	  MCUboot itself to load update images into flash over a UART.