sim: Fit unit tests to larger write align values

Signed-off-by: Gustavo Henrique Nihei <gustavo.nihei@espressif.com>
diff --git a/sim/mcuboot-sys/csupport/run.c b/sim/mcuboot-sys/csupport/run.c
index 6c61228..cb2016b 100644
--- a/sim/mcuboot-sys/csupport/run.c
+++ b/sim/mcuboot-sys/csupport/run.c
@@ -477,5 +477,5 @@
 
 uint32_t boot_magic_sz(void)
 {
-    return BOOT_MAGIC_SZ;
+    return BOOT_MAGIC_ALIGN_SIZE;
 }