udelay.c: sync internal_sleep() function from upstream

Needed for buspirate sync.

BUG=b:152815694
BRANCH=none
TEST=builds

Signed-off-by: Nikolai Artemiev <nartemiev@chromium.org>
Change-Id: I16356604a30c578ab382ff234e87f981ab22e703
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/flashrom/+/2306631
Tested-by: Nikolai Artemiev <nartemiev@google.com>
Tested-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Commit-Queue: Nikolai Artemiev <nartemiev@google.com>
diff --git a/programmer.h b/programmer.h
index 4f696f5..e75ff4f 100644
--- a/programmer.h
+++ b/programmer.h
@@ -245,6 +245,7 @@
 /* udelay.c */
 void myusec_delay(unsigned int usecs);
 void myusec_calibrate_delay(void);
+void internal_sleep(unsigned int usecs);
 void internal_delay(unsigned int usecs);
 void internal_sleep(unsigned int usecs);