arm: mvebu: drivers/ddr: Move Armada XP DDR init code into new directory

With the upcoming addition of the Armada 38x DDR support, which is not
compatible to the Armada XP DDR init code, we need to introduce a new
directory infrastructure. To support multiple Marvell DDR controller.

This will be the new structure:

     drivers/ddr/marvell/axp
     Supporting Armada XP (AXP) devices (and perhaps Armada 370)

     drivers/ddr/marvell/a38x
     Supporting Armada 38x devices (and perhaps Armada 39x)

Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/include/configs/db-mv784mp-gp.h b/include/configs/db-mv784mp-gp.h
index aeddbf9..41e6fdc 100644
--- a/include/configs/db-mv784mp-gp.h
+++ b/include/configs/db-mv784mp-gp.h
@@ -138,7 +138,7 @@
 #define CONFIG_SYS_SPI_U_BOOT_OFFS	0x20000
 
 /* Enable DDR support in SPL (DDR3 training from Marvell bin_hdr) */
-#define CONFIG_SYS_MVEBU_DDR
+#define CONFIG_SYS_MVEBU_DDR_AXP
 #define CONFIG_SPD_EEPROM		0x4e
 
 #endif /* _CONFIG_DB_MV7846MP_GP_H */