Fix booting pentium+ with dodgy TSC

We handle a broken tsc these days, so no need to panic.  We clear the
TSC bit when tsc_init decides it's unreliable (eg.  under lguest w/ bad
host TSC), leading to bogus panic.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/x86/kernel/cpu/bugs.c

@@ -142,14 +142,6 @@ static void __init check_config(void)
 		panic("Kernel requires i486+ for 'invlpg' and other features");
 #endif
 
-/*
- * If we configured ourselves for a TSC, we'd better have one!
- */
-#ifdef CONFIG_X86_TSC
-	if (!cpu_has_tsc)
-		panic("Kernel compiled for Pentium+, requires TSC feature!");
-#endif
-
 /*
  * If we were told we had a good local APIC, check for buggy Pentia,
  * i.e. all B steppings and the C2 stepping of P54C when using their