ARM: Add workaround for Cortex-A9 errata 761320

Full cache line writes to the same memory region from at least two
processors might deadlock the processor. Exists on r1, r2, r3
revisions.

Signed-off-by: Nitin Garg <nitin.garg@freescale.com>
Acked-by: Fabio Estevam <fabio.estevam@freescale.com>
diff --git a/README b/README
index 00127a7..da85c89 100644
--- a/README
+++ b/README
@@ -567,6 +567,7 @@
 		CONFIG_ARM_ERRATA_743622
 		CONFIG_ARM_ERRATA_751472
 		CONFIG_ARM_ERRATA_794072
+		CONFIG_ARM_ERRATA_761320
 
 		If set, the workarounds for these ARM errata are applied early
 		during U-Boot startup. Note that these options force the