Finish conversion CONFIG_SYS_NAND_SELF_INIT to Kconfig

In order to finish this conversion we need to add a symbols for
SPL_SYS_NAND_SELF_INIT and TPL_SYS_NAND_SELF_INIT as there are cases
there where we need to, or need to not, use that framework as things
stand.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/include/nand.h b/include/nand.h
index 09dbda4..70c1286 100644
--- a/include/nand.h
+++ b/include/nand.h
@@ -10,22 +10,6 @@
 
 #include <config.h>
 
-/*
- * All boards using a given driver must convert to self-init
- * at the same time, so do it here.  When all drivers are
- * converted, this will go away.
- */
-#ifdef CONFIG_SPL_BUILD
-#if defined(CONFIG_NAND_FSL_ELBC) || defined(CONFIG_NAND_FSL_IFC)
-#define CONFIG_SYS_NAND_SELF_INIT
-#endif
-#else
-#if defined(CONFIG_NAND_FSL_ELBC) || defined(CONFIG_NAND_ATMEL)\
-	|| defined(CONFIG_NAND_FSL_IFC)
-#define CONFIG_SYS_NAND_SELF_INIT
-#endif
-#endif
-
 extern void nand_init(void);
 unsigned long nand_size(void);
 
@@ -34,7 +18,7 @@
 
 int nand_mtd_to_devnum(struct mtd_info *mtd);
 
-#ifdef CONFIG_SYS_NAND_SELF_INIT
+#if CONFIG_IS_ENABLED(SYS_NAND_SELF_INIT)
 void board_nand_init(void);
 int nand_register(int devnum, struct mtd_info *mtd);
 #else