zephyr: TinyCBOR has been removed from interface libraries

It is no longer needed to add TINYCBOR to list of interface libraries.

Signed-off-by: Dominik Ermel <dominik.ermel@nordicsemi.no>
diff --git a/boot/zephyr/CMakeLists.txt b/boot/zephyr/CMakeLists.txt
index 7905278..891b75d 100644
--- a/boot/zephyr/CMakeLists.txt
+++ b/boot/zephyr/CMakeLists.txt
@@ -198,11 +198,6 @@
   zephyr_include_directories(${BOOT_DIR}/boot_serial/include)
   zephyr_include_directories(include)
 
-  zephyr_link_libraries_ifdef(
-    CONFIG_TINYCBOR
-    TINYCBOR
-    )
-
   zephyr_include_directories_ifdef(
     CONFIG_BOOT_ERASE_PROGRESSIVELY
     ${BOOT_DIR}/bootutil/src