board: axs10x - support v3 mother-board

There're 2 versions of motherboards that could be used in ARC SDP.
The only important difference for U-Boot is different NAND IC in use:
 [1] v2 board (we used to support up until now) sports MT29F4G08ABADAWP
while
 [2] v3 board sports MT29F4G16ABADAWP

They are almost the same except data bus width 8-bit in [1] and 16-bit
in [2]. And for proper support of 16-bit data bus we have to pass
NAND_BUSWIDTH_16 option to NAND driver core - which we do now knowing
board type we're running on.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
diff --git a/board/synopsys/axs101/nand.c b/board/synopsys/axs101/nand.c
index ff35286..4be52e2 100644
--- a/board/synopsys/axs101/nand.c
+++ b/board/synopsys/axs101/nand.c
@@ -9,6 +9,9 @@
 #include <malloc.h>
 #include <nand.h>
 #include <asm/io.h>
+#include "axs10x.h"
+
+DECLARE_GLOBAL_DATA_PTR;
 
 #define BUS_WIDTH	8		/* AXI data bus width in bytes	*/
 
@@ -232,5 +235,9 @@
 	nand->write_buf = axs101_nand_write_buf;
 	nand->read_buf = axs101_nand_read_buf;
 
+	/* MBv3 has NAND IC with 16-bit data bus */
+	if (gd->board_type == AXS_MB_V3)
+		nand->options |= NAND_BUSWIDTH_16;
+
 	return 0;
 }