Kconfig: Fix "warning: style: quotes recommended" warnings

We have three warnings about needing to use quotes around some strings
in Kconfig files today. In two of these cases we can just add the
missing strings. In the case of INTEL_PINCTRL_PADCFG_PADTOL the symbol
is never referenced and should be dropped.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/Kconfig b/Kconfig
index 70dc385..a508c54 100644
--- a/Kconfig
+++ b/Kconfig
@@ -748,7 +748,7 @@
 
 source "env/Kconfig"
 
-menu Networking
+menu "Networking"
 
 choice
 	prompt "Networking stack"