configs: atmel: sama5d4_xplained_mmc: enable HW PMECC

NAND:  BUG at drivers/mtd/nand/raw/nand_base.c:4361/nand_scan_tail()!

This board has a NAND flash enabled, and it requires the HW PMECC in order
to correctly probe this flash.
In the NAND flash configuration , this is selected by the GENERATE_PMECC_HEADER
which is not needed for mmc configuration.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
diff --git a/configs/sama5d4_xplained_mmc_defconfig b/configs/sama5d4_xplained_mmc_defconfig
index f673832..0504b4e 100644
--- a/configs/sama5d4_xplained_mmc_defconfig
+++ b/configs/sama5d4_xplained_mmc_defconfig
@@ -59,6 +59,8 @@
 CONFIG_GENERIC_ATMEL_MCI=y
 CONFIG_NAND=y
 CONFIG_NAND_ATMEL=y
+CONFIG_ATMEL_NAND_HW_PMECC=y
+CONFIG_PMECC_CAP=8
 CONFIG_DM_SPI_FLASH=y
 CONFIG_SPI_FLASH=y
 CONFIG_SF_DEFAULT_SPEED=30000000