liblog: add pstore read

Used to pull the Android log messages after a reboot. Adding
an ANDROID_LOG_PSTORE flag to the mode parameter in calls to
android_logger_list_alloc() and android_logger_list_alloc_time().
The side effects are that android_logger_clear() and
android_logger_list_read() will react with the user space
pstore driver. Forms a companion to the pstore console logs.

Change-Id: I7bb07b87b3bf73f059a21af3f810af37c7715b6d
diff --git a/include/log/logger.h b/include/log/logger.h
index 570f02b..f030dab 100644
--- a/include/log/logger.h
+++ b/include/log/logger.h
@@ -159,6 +159,7 @@
 #define ANDROID_LOG_RDWR     O_RDWR
 #define ANDROID_LOG_ACCMODE  O_ACCMODE
 #define ANDROID_LOG_NONBLOCK O_NONBLOCK
+#define ANDROID_LOG_PSTORE   0x80000000
 
 struct logger_list *android_logger_list_alloc(int mode,
                                               unsigned int tail,