boot: bootutil: bootutil_misc: Fix max image size for single images

Fixes wrongly including swap and trailer sizes for single image
builds which reduced the maximum size of applications, these areas
are not used or applicable with single image modes

Signed-off-by: Jamie McCrae <jamie.mccrae@nordicsemi.no>

Author: nordicjm

boot/bootutil/src/bootutil_misc.c

@@ -99,6 +99,12 @@ fih_ret boot_fih_memequal(const void *s1, const void *s2, size_t n)
 static inline uint32_t
 boot_trailer_info_sz(void)
 {
+#if defined(MCUBOOT_SINGLE_APPLICATION_SLOT) ||      \
+    defined(MCUBOOT_FIRMWARE_LOADER) ||              \
+    defined(MCUBOOT_SINGLE_APPLICATION_SLOT_RAM_LOAD)
+    /* Single image MCUboot modes do not have a trailer */
+    return 0;
+#else
     return (
 #ifdef MCUBOOT_ENC_IMAGES
            /* encryption keys */
@@ -112,6 +118,7 @@ boot_trailer_info_sz(void)
            BOOT_MAX_ALIGN * 4                     +
            BOOT_MAGIC_ALIGN_SIZE
            );
+#endif
 }
 
 /*
@@ -121,7 +128,14 @@ boot_trailer_info_sz(void)
 static inline uint32_t
 boot_status_entry_sz(uint32_t min_write_sz)
 {
+#if defined(MCUBOOT_SINGLE_APPLICATION_SLOT) ||      \
+    defined(MCUBOOT_FIRMWARE_LOADER) ||              \
+    defined(MCUBOOT_SINGLE_APPLICATION_SLOT_RAM_LOAD)
+    /* Single image MCUboot modes do not have a swap status fields */
+    return 0;
+#else
     return BOOT_STATUS_STATE_COUNT * min_write_sz;
+#endif
 }
 
 uint32_t