sim: Fix MCUBOOT_SWAP_USING_SCRATCH defined in direct-xip and ram-load

When 'direct-xip' or 'ram-load' features were enabled,
CONFIG_BOOT_SWAP_USING_SCRATCH and MCUBOOT_SWAP_USING_SCRATCH were
defined even though swap using scratch wasn't used. This commit fixes
the issue.

Signed-off-by: Thomas Altenbach <thomas.altenbach@legrand.com>
diff --git a/sim/mcuboot-sys/build.rs b/sim/mcuboot-sys/build.rs
index 4221292..ea17d80 100644
--- a/sim/mcuboot-sys/build.rs
+++ b/sim/mcuboot-sys/build.rs
@@ -255,7 +255,7 @@
 
     if swap_move {
         conf.conf.define("MCUBOOT_SWAP_USING_MOVE", None);
-    } else if !overwrite_only {
+    } else if !overwrite_only && !direct_xip && !ram_load {
         conf.conf.define("CONFIG_BOOT_SWAP_USING_SCRATCH", None);
         conf.conf.define("MCUBOOT_SWAP_USING_SCRATCH", None);
     }