Blackfin: set default boot SPI CS for BF538/BF539

The BF538/BF539 use CS2 for booting off of rather than CS1 like newer
Blackfin parts.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/board/bf537-stamp/spi_flash.c b/board/bf537-stamp/spi_flash.c
index 11a2803..a99c3fa 100644
--- a/board/bf537-stamp/spi_flash.c
+++ b/board/bf537-stamp/spi_flash.c
@@ -182,8 +182,8 @@
  *	BF533, BF561: SSEL2
  */
 #ifndef CONFIG_SPI_FLASH_SSEL
-# if defined(__ADSPBF531__) || defined(__ADSPBF532__) || \
-     defined(__ADSPBF533__) || defined(__ADSPBF561__)
+# if defined(__ADSPBF531__) || defined(__ADSPBF532__) || defined(__ADSPBF533__) || \
+     defined(__ADSPBF538__) || defined(__ADSPBF539__) || defined(__ADSPBF561__)
 #  define CONFIG_SPI_FLASH_SSEL 2
 # else
 #  define CONFIG_SPI_FLASH_SSEL 1