am33xx_spl_bch: simple SPL nand loader for AM33XX

AM33XX with BCH8 can't work with nand_spl_simple correctly
because custom read_page implementation is required for proper
syndrome generation.

This simple driver mostly duplicates nand_spl_simple but has
nand_read_page changed to suit our needs.

Signed-off-by: Ilya Yanok <ilya.yanok@cogentembedded.com>
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index beb99ca..5322f3a 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -30,6 +30,7 @@
 ifdef CONFIG_SPL_NAND_SIMPLE
 COBJS-y += nand_spl_simple.o
 endif
+COBJS-$(CONFIG_SPL_NAND_AM33XX_BCH) += am335x_spl_bch.o
 ifdef CONFIG_SPL_NAND_LOAD
 COBJS-y	+= nand_spl_load.o
 endif