powerpc/mpc85xx: Update workaround for DDR erratum A-004934

The workaround has been updated to use a slightly different magic number.
Change from 0x00003000 to 0x30003000.

Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>

arch/powerpc/cpu/mpc85xx/ddr-gen3.c

@@ -142,7 +142,7 @@ void fsl_ddr_set_memctl_regs(const fsl_ddr_cfg_regs_t *regs,
 		}
 	}
 #ifdef CONFIG_SYS_FSL_ERRATUM_A_004934
-	out_be32(&ddr->debug[28], 0x00003000);
+	out_be32(&ddr->debug[28], 0x30003000);
 #endif
 
 #ifdef CONFIG_SYS_FSL_ERRATUM_DDR_A003474