boot/zephyr: renamed single-image mode to single-application-slot mode

The terms "single-image boot" and the "single image application"
of Zephyr are confused. It might be might be understood as one-pair image
dual-bank mode in comparison to multi-image mode.

This patch replaces CONFIG_SINGLE_IMAGE_DFU by
CONFIG_SINGLE_APPLICATION_SLOT name,
which makes this mode name unambiguous.

fixes #800

Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>

fix
diff --git a/boot/zephyr/include/mcuboot_config/mcuboot_config.h b/boot/zephyr/include/mcuboot_config/mcuboot_config.h
index 530e8dc..d395489 100644
--- a/boot/zephyr/include/mcuboot_config/mcuboot_config.h
+++ b/boot/zephyr/include/mcuboot_config/mcuboot_config.h
@@ -58,8 +58,8 @@
 #define MCUBOOT_OVERWRITE_ONLY_FAST
 #endif
 
-#ifdef CONFIG_SINGLE_IMAGE_DFU
-#define MCUBOOT_SINGLE_IMAGE_DFU 1
+#ifdef CONFIG_SINGLE_APPLICATION_SLOT
+#define MCUBOOT_SINGLE_APPLICATION_SLOT 1
 #else
 
 #ifdef CONFIG_BOOT_SWAP_USING_MOVE
@@ -80,7 +80,7 @@
 #define MCUBOOT_SWAP_SAVE_ENCTLV 1
 #endif
 
-#endif /* CONFIG_SINGLE_IMAGE_DFU */
+#endif /* CONFIG_SINGLE_APPLICATION_SLOT */
 
 #ifdef CONFIG_LOG
 #define MCUBOOT_HAVE_LOGGING 1
diff --git a/boot/zephyr/include/sysflash/sysflash.h b/boot/zephyr/include/sysflash/sysflash.h
index f651779..99ca273 100644
--- a/boot/zephyr/include/sysflash/sysflash.h
+++ b/boot/zephyr/include/sysflash/sysflash.h
@@ -6,7 +6,7 @@
 #include <devicetree.h>
 #include <mcuboot_config/mcuboot_config.h>
 
-#ifndef CONFIG_SINGLE_IMAGE_DFU
+#ifndef CONFIG_SINGLE_APPLICATION_SLOT
 
 #if (MCUBOOT_IMAGE_NUMBER == 1)
 /*
@@ -43,7 +43,7 @@
 #define FLASH_AREA_IMAGE_SCRATCH    FLASH_AREA_ID(image_scratch)
 #endif
 
-#else /* CONFIG_SINGLE_IMAGE_DFU */
+#else /* CONFIG_SINGLE_APPLICATION_SLOT */
 
 #define FLASH_AREA_IMAGE_PRIMARY(x)	FLASH_AREA_ID(image_0)
 #define FLASH_AREA_IMAGE_SECONDARY(x)	FLASH_AREA_ID(image_0)
@@ -53,6 +53,6 @@
  */
 #define FLASH_AREA_IMAGE_SCRATCH	0
 
-#endif /* CONFIG_SINGLE_IMAGE_DFU */
+#endif /* CONFIG_SINGLE_APPLICATION_SLOT */
 
 #endif /* __SYSFLASH_H__ */
diff --git a/boot/zephyr/include/target.h b/boot/zephyr/include/target.h
index d585b9c..1b0c8f5 100644
--- a/boot/zephyr/include/target.h
+++ b/boot/zephyr/include/target.h
@@ -37,8 +37,8 @@
     (defined(CONFIG_XTENSA) && !defined(JEDEC_SPI_NOR_0_LABEL)) || \
     !defined(FLASH_ALIGN) ||                  \
     !(FLASH_AREA_LABEL_EXISTS(image_0)) || \
-    !(FLASH_AREA_LABEL_EXISTS(image_1) || CONFIG_SINGLE_IMAGE_DFU) || \
-    (!defined(CONFIG_BOOT_SWAP_USING_MOVE) && !FLASH_AREA_LABEL_EXISTS(image_scratch) && !defined(CONFIG_SINGLE_IMAGE_DFU))
+    !(FLASH_AREA_LABEL_EXISTS(image_1) || CONFIG_SINGLE_APPLICATION_SLOT) || \
+    (!defined(CONFIG_BOOT_SWAP_USING_MOVE) && !FLASH_AREA_LABEL_EXISTS(image_scratch) && !defined(CONFIG_SINGLE_APPLICATION_SLOT))
 #error "Target support is incomplete; cannot build mcuboot."
 #endif