ARM: Add workaround for Cortex-A9 errata 794072

A short loop including a DMB instruction might cause a denial of
service on another processor which executes a CP15 broadcast operation.
Exists on r1, r2, r3, r4 revisions.

Signed-off-by: Nitin Garg <nitin.garg@freescale.com>
Acked-by: Dirk Behme <dirk.behme@de.bosch.com>
diff --git a/README b/README
index 216f0c7..00127a7 100644
--- a/README
+++ b/README
@@ -566,6 +566,7 @@
 		CONFIG_ARM_ERRATA_742230
 		CONFIG_ARM_ERRATA_743622
 		CONFIG_ARM_ERRATA_751472
+		CONFIG_ARM_ERRATA_794072
 
 		If set, the workarounds for these ARM errata are applied early
 		during U-Boot startup. Note that these options force the