powerpc/85xx: Add the workaround for erratum CPC-A002 (enable on P4080)

CoreNet Platform Cache single-bit tag error scrubbing will cause tag
corruption.  Disable the feature to workaround the issue.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/cpu/mpc85xx/cmd_errata.c b/arch/powerpc/cpu/mpc85xx/cmd_errata.c
index 4e2cb4a..ae6af4f 100644
--- a/arch/powerpc/cpu/mpc85xx/cmd_errata.c
+++ b/arch/powerpc/cpu/mpc85xx/cmd_errata.c
@@ -59,6 +59,10 @@
 #if defined(CONFIG_SYS_FSL_ERRATUM_ESDHC136)
 	puts("Work-around for Erratum ESDHC136 enabled\n");
 #endif
+#ifdef CONFIG_SYS_FSL_ERRATUM_CPC_A002
+	puts("Work-around for Erratum CPC-A002 enabled\n");
+#endif
+
 	return 0;
 }
 
diff --git a/arch/powerpc/cpu/mpc85xx/cpu_init.c b/arch/powerpc/cpu/mpc85xx/cpu_init.c
index 354b222..c822d87 100644
--- a/arch/powerpc/cpu/mpc85xx/cpu_init.c
+++ b/arch/powerpc/cpu/mpc85xx/cpu_init.c
@@ -142,6 +142,10 @@
 		u32 cpccfg0 = in_be32(&cpc->cpccfg0);
 		size += CPC_CFG0_SZ_K(cpccfg0);
 
+#ifdef CONFIG_SYS_FSL_ERRATUM_CPC_A002
+		setbits_be32(&cpc->cpchdbcr0, CPC_HDBCR0_TAG_ECC_SCRUB_DIS);
+#endif
+
 		out_be32(&cpc->cpccsr0, CPC_CSR0_CE | CPC_CSR0_PE);
 		/* Read back to sync write */
 		in_be32(&cpc->cpccsr0);