boot:zephyr: CONFIG_LOG_MINIMAL converted to CONFIG_LOG_MODE_MINIMAL

CONFIG_LOG_MINIMAL was replaced by CONFIG_LOG_MODE_MINIMAL since
https://github.com/zephyrproject-rtos/zephyr/pull/31404 PR was
merged.
CONFIG_LOG_MINIMAL is still emitted as legacy property, but
can't be assigned so prj.conf was fixed.

Signed-off-by: Gerard Marull-Paretas <gerard@teslabs.com>
Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>
diff --git a/boot/zephyr/main.c b/boot/zephyr/main.c
index e1697db..747d36c 100644
--- a/boot/zephyr/main.c
+++ b/boot/zephyr/main.c
@@ -51,8 +51,14 @@
 #include <arm_cleanup.h>
 #endif
 
+/* CONFIG_LOG_MINIMAL is the legacy Kconfig property,
+ * replaced by CONFIG_LOG_MODE_MINIMAL.
+ */
+#define ZEPHYR_LOG_MODE_MINIMAL (defined(CONFIG_LOG_MODE_MINIMAL) ||\
+                                 defined(CONFIG_LOG_MINIMAL))
+
 #if defined(CONFIG_LOG) && !defined(CONFIG_LOG_IMMEDIATE) && \
-    !defined(CONFIG_LOG_MINIMAL)
+    !ZEPHYR_LOG_MODE_MINIMAL
 #ifdef CONFIG_LOG_PROCESS_THREAD
 #warning "The log internal thread for log processing can't transfer the log"\
          "well for MCUBoot."
@@ -259,7 +265,7 @@
 #endif
 
 #if defined(CONFIG_LOG) && !defined(CONFIG_LOG_IMMEDIATE) &&\
-    !defined(CONFIG_LOG_PROCESS_THREAD) && !defined(CONFIG_LOG_MINIMAL)
+    !defined(CONFIG_LOG_PROCESS_THREAD) && !ZEPHYR_LOG_MODE_MINIMAL
 /* The log internal thread for log processing can't transfer log well as has too
  * low priority.
  * Dedicated thread for log processing below uses highest application