bootutil: mynewt: Improve BOOTUTIL configuration

This makes bootutil_public.c the only source file built for
non-bootloader builds, so we don't have to set bootutil syscfgs
that are relevant only to the bootloader when building
an application.

Signed-off-by: Michal Gorecki <michal.gorecki@codecoup.pl>

Author: m-gorecki

boot/bootutil/pkg.yml

@@ -47,6 +47,9 @@ pkg.ign_files:
     - "ed25519_psa.c"       # Currently no PSA for mynewet
     - "encrypted_psa.c"
 
+pkg.source_files.!BOOT_LOADER:
+    - "src/bootutil_public.c"
+
 pkg.deps.BOOTUTIL_USE_MBED_TLS:
     - "@apache-mynewt-core/crypto/mbedtls"