configs: Remove a number of unreferenced CONFIG options.

There are a large number of options under CONFIG_SYS (but some of these
are elsewhere, spotted while cleaning CONFIG_SYS) that are never
referenced, or only used slightly later in the config file.  Remove or
restructure these.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/include/configs/s5p4418_nanopi2.h b/include/configs/s5p4418_nanopi2.h
index 4359357..ae94f0e 100644
--- a/include/configs/s5p4418_nanopi2.h
+++ b/include/configs/s5p4418_nanopi2.h
@@ -18,11 +18,10 @@
 /*-----------------------------------------------------------------------
  *  System memory Configuration
  */
-#define CONFIG_SYS_MEM_SIZE		0x40000000
 #define CONFIG_SYS_SDRAM_BASE		0x71000000
 
 /*
- * "(CONFIG_SYS_MEM_SIZE - CONFIG_SYS_RESERVE_MEM_SIZE)" has been used in
+ * "(0x40000000 - CONFIG_SYS_RESERVE_MEM_SIZE)" has been used in
  * u-boot nanopi2-v2016.01.
  * This is not working anymore because boot_fdt_add_mem_rsv_regions() in
  * common/image-fdt.c has been extended: