vpl: Ensure all VPL symbols in Kconfig have some VPL dependency

Tighten up symbol dependencies in a number of places.  Ensure that a VPL
specific option has at least a direct dependency on VPL.  In places
where it's clear that we depend on something more specific, use that
dependency instead.

Reported-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/lib/Kconfig b/lib/Kconfig
index ccbc52d..c9f9ddc 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -783,6 +783,7 @@
 
 config VPL_OF_LIBFDT
 	bool "Enable the FDT library for VPL"
+	depends on VPL
 	default y if VPL_OF_CONTROL && !VPL_OF_PLATDATA
 	help
 	  This enables the FDT library (libfdt). It provides functions for
@@ -793,7 +794,7 @@
 
 config VPL_OF_LIBFDT_ASSUME_MASK
 	hex "Mask of conditions to assume for libfdt"
-	depends on VPL_OF_LIBFDT || FIT
+	depends on VPL_OF_LIBFDT || (FIT && VPL)
 	default 0xff
 	help
 	  Use this to change the assumptions made by libfdt in SPL about the