Add programmer-specific delay functions

Add external programmer delay functions so external programmers can
handle the delay on their own if needed.

Corresponding to flashrom svn r578.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Uwe Hermann <uwe@hermann-uwe.de>
Acked-by: Urja Rannikko <urjaman@gmail.com>
diff --git a/it87spi.c b/it87spi.c
index 2528b91..e90cf8d 100644
--- a/it87spi.c
+++ b/it87spi.c
@@ -220,7 +220,7 @@
 	 * This usually takes 1-10 ms, so wait in 1 ms steps.
 	 */
 	while (spi_read_status_register() & JEDEC_RDSR_BIT_WIP)
-		usleep(1000);
+		programmer_delay(1000);
 	return 0;
 }
 
@@ -245,7 +245,7 @@
 			return result;
 		spi_byte_program(i, buf[i]);
 		while (spi_read_status_register() & JEDEC_RDSR_BIT_WIP)
-			myusec_delay(10);
+			programmer_delay(10);
 	}
 	/* resume normal ops... */
 	OUTB(0x20, it8716f_flashport);