spl: Ensure all SPL symbols in Kconfig have some SPL dependency

Tighten up symbol dependencies in a number of places.  Ensure that a SPL
specific option has at least a direct dependency on SPL.  In places
where it's clear that we depend on something more specific, use that
dependency instead.  This means in a very small number of places we can
drop redundant dependencies.

Reported-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index f10d1aa..eae1c8d 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -3,7 +3,7 @@
 
 config SPL_FIRMWARE
 	bool "Enable Firmware driver support in SPL"
-	depends on FIRMWARE
+	depends on FIRMWARE && SPL
 
 config SPL_ARM_PSCI_FW
 	bool