powerpc: mpc85xx: Implement CPU erratum A-007907 for secondary cores

Commit 06ad970b ("powerpc: mpc85xx: Implemente workaround for CPU
erratum A-007907") clears L1CSR2 for the boot core, but other cores
don't run through the workaround. Add similar code for secondary
cores to clear DCSTASHID field in L1CSR2 register.
Signed-off-by: NYork Sun <york.sun@nxp.com>

arch/powerpc/cpu/mpc85xx/release.S

@@ -184,12 +184,18 @@ __secondary_start_page:
 
 	mtspr	SPRN_PIR,r4	/* write to PIR register */
 
+#ifdef CONFIG_SYS_FSL_ERRATUM_A007907
+	mfspr	r8, L1CSR2
+	clrrwi	r8, r8, 10	/* clear bit [54-63] DCSTASHID */
+	mtspr	L1CSR2, r8
+#else
 #ifdef CONFIG_SYS_CACHE_STASHING
 	/* set stash id to (coreID) * 2 + 32 + L1 CT (0) */
 	slwi	r8,r4,1
 	addi	r8,r8,32
 	mtspr	L1CSR2,r8
 #endif
+#endif	/* CONFIG_SYS_FSL_ERRATUM_A007907 */
 
 #if defined(CONFIG_SYS_P4080_ERRATUM_CPU22) || \
 	defined(CONFIG_SYS_FSL_ERRATUM_NMG_CPU_A011)