mynewt: Igore swap_scratch.c for single application slot

swap_scratch.c requires definition of SLOT1, in single application
slot build it's not needed and file would not be used anyway so
now it is removed from mynewt build

Signed-off-by: Jerzy Kasenberg <jerzy.kasenberg@codecoup.pl>

boot/bootutil/pkg.yml

@@ -43,6 +43,7 @@ pkg.deps:
 
 pkg.ign_files.BOOTUTIL_SINGLE_APPLICATION_SLOT:
     - "loader.c"
+    - "swap_scratch.c"
 
 pkg.deps.BOOTUTIL_USE_MBED_TLS:
     - "@apache-mynewt-core/crypto/mbedtls"

boot/mynewt/pkg.yml

@@ -37,6 +37,8 @@ pkg.deps:
 
 pkg.ign_files.!BOOTUTIL_SINGLE_APPLICATION_SLOT:
     - "single_loader.c"
+pkg.ign_files.BOOTUTIL_SINGLE_APPLICATION_SLOT:
+    - "swap_scratch.c"
 
 pkg.deps.BOOTUTIL_NO_LOGGING:
     - "@apache-mynewt-core/sys/console/stub"