Rename bootretry functions and remove #ifdefs

Add a bootretry_ prefix to these two functions, and remove the need for
the #ifdef around everything (it moves to the Makefile).

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/common/bootretry.c b/common/bootretry.c
index 12653c0..2d82798 100644
--- a/common/bootretry.c
+++ b/common/bootretry.c
@@ -21,7 +21,7 @@
 /***************************************************************************
  * initialize command line timeout
  */
-void init_cmd_timeout(void)
+void bootretry_init_cmd_timeout(void)
 {
 	char *s = getenv("bootretry");
 
@@ -37,7 +37,7 @@
 /***************************************************************************
  * reset command line timeout to retry_time seconds
  */
-void reset_cmd_timeout(void)
+void bootretry_reset_cmd_timeout(void)
 {
 	endtime = endtick(retry_time);
 }