kgdb: Add the ability to schedule a breakpoint via a tasklet

Some kgdb I/O modules require the ability to create a breakpoint
tasklet, such as kgdboc and external modules such as kgdboe.  The
breakpoint tasklet is used as an asynchronous entry point into the
debugger which will have a different function scope than the current
execution path where it might not be safe to have an inline
breakpoint.  This is true of some of the kgdb I/O drivers which share
code with kgdb and rest of the kernel users.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h
index 19d1b29..ee007ea 100644
--- a/include/linux/kgdb.h
+++ b/include/linux/kgdb.h
@@ -271,6 +271,7 @@
 extern int kgdb_hex2mem(char *buf, char *mem, int count);
 
 extern int kgdb_isremovedbreak(unsigned long addr);
+extern void kgdb_schedule_breakpoint(void);
 
 extern int
 kgdb_handle_exception(int ex_vector, int signo, int err_code,