boot: zephyr: migrate to new log subystem

The old log subsystem has been deprecated in Zephyr.
Migrate to the new subsystem to avoid compilation warnings.

In-place log processing is selected as it is required as MCUBoot is
one thread application.

Signed-off-by: Emanuele Di Santo <emdi@nordicsemi.no>
Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>
diff --git a/boot/zephyr/flash_map_legacy.c b/boot/zephyr/flash_map_legacy.c
index 69803fe..b217947 100644
--- a/boot/zephyr/flash_map_legacy.c
+++ b/boot/zephyr/flash_map_legacy.c
@@ -49,6 +49,8 @@
 #define FLASH_AREA_IMAGE_SECTOR_SIZE FLASH_AREA_IMAGE_SCRATCH_SIZE
 #endif
 
+MCUBOOT_LOG_MODULE_DECLARE(mcuboot);
+
 /*
  * Lookup the sector map for a given flash area.  This should fill in
  * `ret` with all of the sectors in the area.  `*cnt` will be set to