m28evk/mx28evk: fix nand_update_full

- since commit 418396e212 nand write.raw
can take the number of page to be written as an argument. nand_update_full
is passing the size (in bytes) to nand write.raw. This value was previously
ignored but now breaks the write.
- this patch updates the default environment of these boards to provide a
pagecount instead of a size to nand write.raw.
- tested on a mx28evk with a 4k page NAND and on a custom board with a
2k page NAND.

Signed-off-by: Eric Bénard <eric@eukrea.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>

include/configs/m28evk.h

@@ -297,7 +297,7 @@
 		"if tftp ${update_nand_full_filename} ; then "		\
 		"run update_nand_get_fcb_size ; "			\
 		"nand scrub -y 0x0 ${filesize} ; "			\
-		"nand write.raw ${loadaddr} 0x0 ${update_nand_fcb} ; "	\
+		"nand write.raw ${loadaddr} 0x0 ${fcb_sz} ; "	\
 		"setexpr update_off ${loadaddr} + ${update_nand_fcb} ; " \
 		"setexpr update_sz ${filesize} - ${update_nand_fcb} ; " \
 		"nand write ${update_off} ${update_nand_fcb} ${update_sz} ; " \

include/configs/mx28evk.h

@@ -263,7 +263,7 @@
 		"if tftp ${update_nand_full_filename} ; then " \
 		"run update_nand_get_fcb_size ; " \
 		"nand scrub -y 0x0 ${filesize} ; " \
-		"nand write.raw ${loadaddr} 0x0 ${update_nand_fcb} ; " \
+		"nand write.raw ${loadaddr} 0x0 ${fcb_sz} ; " \
 		"setexpr update_off ${loadaddr} + ${update_nand_fcb} ; " \
 		"setexpr update_sz ${filesize} - ${update_nand_fcb} ; " \
 		"nand write ${update_off} ${update_nand_fcb} ${update_sz} ; " \