Support reads of arbitrary range

That means you can tell flashrom to read exactly bytes 12345-56789
(start 12345, length 44445) and it will not fetch a single byte more.

Uwe tested this on one LPC, one SPI, and one parallel flash board.

Corresponding to flashrom svn r596.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Uwe Hermann <uwe@hermann-uwe.de>
diff --git a/sb600spi.c b/sb600spi.c
index 259ad27..f4f3492 100644
--- a/sb600spi.c
+++ b/sb600spi.c
@@ -39,10 +39,10 @@
 struct sb600_spi_controller *spi_bar = NULL;
 uint8_t *sb600_spibar;
 
-int sb600_spi_read(struct flashchip *flash, uint8_t *buf)
+int sb600_spi_read(struct flashchip *flash, uint8_t *buf, int start, int len)
 {
 	/* Maximum read length is 8 bytes. */
-	return spi_read_chunked(flash, buf, 8);
+	return spi_read_chunked(flash, buf, start, len, 8);
 }
 
 uint8_t sb600_read_status_register(void)