ARM: at91: sama5d3_xplained: spl: enable PMECC header generation

As sama5d3 xplained support the PMECC. So add the PMECC header for spl
binary. That make ROM loader can use PMECC to avoid error flips in spl
code in nandflash.

Signed-off-by: Josh Wu <josh.wu@atmel.com>
Acked-by: Bo Shen <voice.shen@atmel.com>

include/configs/sama5d3_xplained.h

@@ -246,6 +246,7 @@
 #define CONFIG_SYS_NAND_OOBSIZE		64
 #define CONFIG_SYS_NAND_BLOCK_SIZE	0x20000
 #define CONFIG_SYS_NAND_BAD_BLOCK_POS	0x0
+#define CONFIG_SPL_GENERATE_ATMEL_PMECC_HEADER
 
 #endif