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/en29f002a.c b/en29f002a.c
index 9997581..f4242f5 100644
--- a/en29f002a.c
+++ b/en29f002a.c
@@ -37,7 +37,7 @@
 	chip_writeb(0x55, bios + 0x2AA);
 	chip_writeb(0x90, bios + 0x555);
 
-	myusec_delay(10);
+	programmer_delay(10);
 
 	id1 = chip_readb(bios + 0x100);
 	id2 = chip_readb(bios + 0x101);
@@ -70,7 +70,7 @@
 	chip_writeb(0x55, bios + 0xAAA);
 	chip_writeb(0x90, bios + 0x555);
 
-	myusec_delay(10);
+	programmer_delay(10);
 
 	id1 = chip_readb(bios + 0x100);
 	id2 = chip_readb(bios + 0x101);
@@ -97,7 +97,7 @@
 	chipaddr dst = bios;
 
 	//chip_writeb(0xF0, bios);
-	myusec_delay(10);
+	programmer_delay(10);
 	erase_chip_jedec(flash);
 
 	printf("Programming page: ");