x86/mm: Re-enable DEBUG_TLBFLUSH for X86_32

CONFIG_INVLPG got removed in commit
094ab1db ("x86, 386 removal:
Remove CONFIG_INVLPG").

That commit left one instance of CONFIG_INVLPG untouched, effectively
disabling DEBUG_TLBFLUSH for X86_32. Since all currently supported
x86 CPUs should now be able to support that option, just drop the entire
sub-dependency.
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Link: http://lkml.kernel.org/r/1363262077.1335.71.camel@x61.thuisdomeinSigned-off-by: NIngo Molnar <mingo@kernel.org>

arch/x86/Kconfig.debug

@@ -131,7 +131,7 @@ config DOUBLEFAULT
 
 config DEBUG_TLBFLUSH
 	bool "Set upper limit of TLB entries to flush one-by-one"
-	depends on DEBUG_KERNEL && (X86_64 || X86_INVLPG)
+	depends on DEBUG_KERNEL
 	---help---
 
 	X86-only for now.