Kconfigs: Various: Fix some SPL, TPL and ARM64 dependencies

Several options are presenting themselves on a various boards
where the options are clearly not used.  (ie, arm64 options on
arm9, or SPL/TPL options when SPL or TPL are not defined)

This patch is not attempting to be a complete list of items, but
more like low hanging fruit.

This patch attempts to reduce some of the menuconfig noise
by defining dependencies so they don't appear when not used.

Signed-off-by: Adam Ford <aford173@gmail.com>
diff --git a/Kconfig b/Kconfig
index d2eb744..643bb8c 100644
--- a/Kconfig
+++ b/Kconfig
@@ -163,7 +163,7 @@
 
 config SPL_SYS_MALLOC_F_LEN
 	hex "Size of malloc() pool in SPL before relocation"
-	depends on SYS_MALLOC_F
+	depends on SYS_MALLOC_F && SPL
 	default 0x2800 if RCAR_GEN3
 	default SYS_MALLOC_F_LEN
 	help
@@ -174,7 +174,7 @@
 
 config TPL_SYS_MALLOC_F_LEN
 	hex "Size of malloc() pool in TPL before relocation"
-	depends on SYS_MALLOC_F
+	depends on SYS_MALLOC_F && TPL
 	default SYS_MALLOC_F_LEN
 	help
 	  Before relocation, memory is very limited on many platforms. Still,
@@ -238,6 +238,7 @@
 	string "SPL image used in the combined SPL+U-Boot image"
 	default "spl/boot.bin" if ARCH_AT91 && SPL_NAND_SUPPORT
 	default "spl/u-boot-spl.bin"
+	depends on SPL
 	help
 	  Select the SPL build target that shall be generated by the SPL
 	  build process (default spl/u-boot-spl.bin). This image will be