armv8: fsl-lsch2: enable snoopable sata read and write

By default the SATA IP on the ls1043a/ls1046a SoCs does not
generating coherent/snoopable transactions.  This patch enable
it in the SCFG_SNPCNFGCR register along with sata axicc register.
In addition, the dma-coherent property must be set on the SATA
controller nodes.

Signed-off-by: Tang Yuantian <yuantian.tang@nxp.com>
[York Sun: Reformatted commit message]
Reviewed-by: York Sun <york.sun@nxp.com>
diff --git a/arch/arm/include/asm/arch-fsl-layerscape/soc.h b/arch/arm/include/asm/arch-fsl-layerscape/soc.h
index 0729b7f..58e90d8 100644
--- a/arch/arm/include/asm/arch-fsl-layerscape/soc.h
+++ b/arch/arm/include/asm/arch-fsl-layerscape/soc.h
@@ -61,6 +61,7 @@
 /* ahci port register default value */
 #define AHCI_PORT_PHY_1_CFG    0xa003fffe
 #define AHCI_PORT_TRANS_CFG    0x08000029
+#define AHCI_PORT_AXICC_CFG	0x3fffffff
 
 /* AHCI (sata) register map */
 struct ccsr_ahci {