x86/Kconfig: Make X86_FEATURE_NAMES non-configurable in prompt

While discussing to change the visibility of X86_FEATURE_NAMES (see Link)
in order to remove CONFIG_EMBEDDED, Boris suggested to simply make the
X86_FEATURE_NAMES functionality unconditional.

As a first step, make X86_FEATURE_NAMES disappear from Kconfig. So, as
X86_FEATURE_NAMES defaults to yes, to disable it, one now needs to
modify the .config file before compiling the kernel.
Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/all/20230509084007.24373-1-lukas.bulwahn@gmail.com/

arch/x86/Kconfig

@@ -442,7 +442,7 @@ config SMP
 	  If you don't know what to do here, say N.
 
 config X86_FEATURE_NAMES
-	bool "Processor feature human-readable names" if EMBEDDED
+	bool
 	default y
 	help
 	  This option compiles in a table of x86 feature bits and corresponding