arm: Implement workaround for Cortex-A9 errata 845369

Under very rare timing circumstances, transitioning into streaming
mode might create a data corruption. Present on Two or more processors
or 1 core with ACP, all revisions. This erratum can be worked round
by setting bit[22] of the undocumented Diagnostic Control Register to 1.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Tom Rini <trini@konsulko.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: Stefano Babic <sbabic@denx.de>

arch/arm/Kconfig

@@ -97,6 +97,9 @@ config ARM_ERRATA_833069
 config ARM_ERRATA_833471
 	bool
 
+config ARM_ERRATA_845369
+       bool
+
 config ARM_ERRATA_852421
 	bool
 

arch/arm/cpu/armv7/start.S

@@ -187,6 +187,12 @@ ENTRY(cpu_init_cp15)
 	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
 #endif
 
+#ifdef CONFIG_ARM_ERRATA_845369
+	mrc     p15, 0, r0, c15, c0, 1	@ read diagnostic register
+	orr     r0, r0, #1 << 22	@ set bit #22
+	mcr     p15, 0, r0, c15, c0, 1	@ write diagnostic register
+#endif
+
 	mov	r5, lr			@ Store my Caller
 	mrc	p15, 0, r1, c0, c0, 0	@ r1 has Read Main ID Register (MIDR)
 	mov	r3, r1, lsr #20		@ get variant field