Make am29f040b driver more solid by printing every 4096th flash address

This fixes the timing when flashing over a serial console.

Corresponding to flashrom svn r46 and coreboot v2 svn r2204.
diff --git a/am29f040b.c b/am29f040b.c
index f67127d..7b82331 100644
--- a/am29f040b.c
+++ b/am29f040b.c
@@ -54,8 +54,9 @@
 	int i;
 
 	for (i = 0; i < page_size; i++) {
-		printf("0x%08lx",
-		       (unsigned long) dst - (unsigned long) bios);
+		if( (i & 0xfff) == 0xfff )
+			printf("0x%08lx", (unsigned long) dst - 
+					(unsigned long) bios);
 
 		*(bios + 0x555) = 0xAA;
 		*(bios + 0x2AA) = 0x55;
@@ -65,7 +66,8 @@
 		/* wait for Toggle bit ready */
 		toggle_ready_jedec(bios);
 
-		printf("\b\b\b\b\b\b\b\b\b\b");
+		if( (i & 0xfff) == 0xfff )
+			printf("\b\b\b\b\b\b\b\b\b\b");
 	}
 
 	return (0);
@@ -118,7 +120,7 @@
 	    flash->page_size;
 	volatile uint8_t *bios = flash->virt_addr;
 
-	printf("Programming Page: ");
+	printf("Programming page ");
 	for (i = 0; i < total_size / page_size; i++) {
 		/* erase the page before programming */
 		erase_sector_29f040b(bios, i * page_size);