ppc4xx: Add support for AMCC 405EP Taihu board

Signed-off-by: John Otken <john@softadvances.com>
diff --git a/common/soft_spi.c b/common/soft_spi.c
index 00a57de..e425061 100644
--- a/common/soft_spi.c
+++ b/common/soft_spi.c
@@ -79,7 +79,9 @@
  */
 int  spi_xfer(spi_chipsel_type chipsel, int bitlen, uchar *dout, uchar *din)
 {
+#ifdef CFG_IMMR
 	volatile immap_t *immr = (immap_t *)CFG_IMMR;
+#endif
 	uchar tmpdin  = 0;
 	uchar tmpdout = 0;
 	int   j;