powerpc/mpc85xx:No NOR boot, do not compile IFC errata A003399

IFC errata A003399 is valid for IFC NOR boot i.e.if no on-board NOR flash or
no NOR boot, do not compile its workaround.

Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
diff --git a/README b/README
index cd0336c..c3d6ca5 100644
--- a/README
+++ b/README
@@ -413,6 +413,10 @@
 		See Freescale App Note 4493 for more information about
 		this erratum.
 
+		CONFIG_A003399_NOR_WORKAROUND
+		Enables a workaround for IFC erratum A003399. It is only
+		requred during NOR boot.
+
 		CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
 
 		This is the value to write into CCSR offset 0x18600