zephyr: Change DT_FLASH_AREA_ macros to FLASH_AREA_

As we replace the legacy DT_FLASH_ support use the new FLASH_AREA_
macros.

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>
diff --git a/boot/zephyr/include/sysflash/sysflash.h b/boot/zephyr/include/sysflash/sysflash.h
index e745ffa..66dce1d 100644
--- a/boot/zephyr/include/sysflash/sysflash.h
+++ b/boot/zephyr/include/sysflash/sysflash.h
@@ -13,32 +13,32 @@
  * running in single image mode.
  */
 #define FLASH_AREA_IMAGE_PRIMARY(x)    (((x) == 0) ?                \
-                                         DT_FLASH_AREA_IMAGE_0_ID : \
-                                         DT_FLASH_AREA_IMAGE_0_ID)
+                                         FLASH_AREA_ID(image_0) : \
+                                         FLASH_AREA_ID(image_0))
 #define FLASH_AREA_IMAGE_SECONDARY(x)  (((x) == 0) ?                \
-                                         DT_FLASH_AREA_IMAGE_1_ID : \
-                                         DT_FLASH_AREA_IMAGE_1_ID)
+                                         FLASH_AREA_ID(image_1) : \
+                                         FLASH_AREA_ID(image_1))
 #elif (MCUBOOT_IMAGE_NUMBER == 2)
 /* MCUBoot currently supports only up to 2 updateable firmware images.
  * If the number of the current image is greater than MCUBOOT_IMAGE_NUMBER - 1
  * then a dummy value will be assigned to the flash area macros.
  */
 #define FLASH_AREA_IMAGE_PRIMARY(x)    (((x) == 0) ?                \
-                                         DT_FLASH_AREA_IMAGE_0_ID : \
+                                         FLASH_AREA_ID(image_0) : \
                                         ((x) == 1) ?                \
-                                         DT_FLASH_AREA_IMAGE_2_ID : \
+                                         FLASH_AREA_ID(image_2) : \
                                          255)
 #define FLASH_AREA_IMAGE_SECONDARY(x)  (((x) == 0) ?                \
-                                         DT_FLASH_AREA_IMAGE_1_ID : \
+                                         FLASH_AREA_ID(image_1) : \
                                         ((x) == 1) ?                \
-                                         DT_FLASH_AREA_IMAGE_3_ID : \
+                                         FLASH_AREA_ID(image_3) : \
                                          255)
 #else
 #error "Image slot and flash area mapping is not defined"
 #endif
 
 #if !defined(CONFIG_BOOT_SWAP_USING_MOVE)
-#define FLASH_AREA_IMAGE_SCRATCH    DT_FLASH_AREA_IMAGE_SCRATCH_ID
+#define FLASH_AREA_IMAGE_SCRATCH    FLASH_AREA_ID(image_scratch)
 #endif
 
 #endif /* __SYSFLASH_H__ */