powerpc/c29xpcie: 8k page size NAND boot support base on TPL/SPL

Using the TPL/SPL method to booting from 8k page NAND flash.
	- Add 256kB size SRAM tlb for second step booting;
	- Add spl.c for TPL image boot;
	- Add spl_minimal.c for minimal SPL image;
	- Add C29XPCIE_NAND configure;
	- Modify C29XPCIE.h for nand config and enviroment;

Signed-off-by: Po Liu <Po.Liu@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/board/freescale/c29xpcie/cpld.c b/board/freescale/c29xpcie/cpld.c
index 5cbccff..37722da 100644
--- a/board/freescale/c29xpcie/cpld.c
+++ b/board/freescale/c29xpcie/cpld.c
@@ -89,6 +89,7 @@
 }
 #endif
 
+#ifndef CONFIG_SPL_BUILD
 int cpld_cmd(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	int rc = 0;
@@ -129,3 +130,4 @@
 	"cpld_cmd dump - display the CPLD registers\n"
 #endif
 	);
+#endif