libcamera: log: Add a debug log level

Many of the message logged by the library will be debug messages, we
thus need a debug log level.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/libcamera/include/log.h

@@ -12,6 +12,7 @@
 namespace libcamera {
 
 enum LogSeverity {
+	LogDebug,
 	LogInfo,
 	LogWarning,
 	LogError,

src/libcamera/log.cpp

@@ -23,6 +23,8 @@ namespace libcamera {
 /**
  * \enum LogSeverity
  * Log message severity
+ * \var LogDebug
+ * Debug message
  * \var LogInfo
  * Informational message
  * \var LogWarning
@@ -43,6 +45,7 @@ namespace libcamera {
 static const char *log_severity_name(LogSeverity severity)
 {
 	static const char * const names[] = {
+		" DBG",
 		"INFO",
 		"WARN",
 		" ERR",