boot/zephyr: Fix single image compilation with serial recovery

Fixes mistake in CMakeLits.txt that prevented successful compilation
of single image with serial recovery enabled.

Signed-off-by: Dominik Ermel <dominik.ermel@nordicsemi.no>
diff --git a/boot/zephyr/CMakeLists.txt b/boot/zephyr/CMakeLists.txt
index 121e584..5bc32ac 100644
--- a/boot/zephyr/CMakeLists.txt
+++ b/boot/zephyr/CMakeLists.txt
@@ -99,6 +99,7 @@
   ${BOOT_DIR}/bootutil/src/image_rsa.c
   ${BOOT_DIR}/bootutil/src/image_ec256.c
   ${BOOT_DIR}/bootutil/src/image_ed25519.c
+  ${BOOT_DIR}/bootutil/src/bootutil_misc.c
   )
 
 if(CONFIG_SINGLE_IMAGE_DFU)
@@ -112,7 +113,6 @@
   ${BOOT_DIR}/bootutil/src/swap_misc.c
   ${BOOT_DIR}/bootutil/src/swap_scratch.c
   ${BOOT_DIR}/bootutil/src/swap_move.c
-  ${BOOT_DIR}/bootutil/src/bootutil_misc.c
   ${BOOT_DIR}/bootutil/src/caps.c
   )
 endif()