Export native_read_tsc

Otherwise modular tcrypt, kvm-intel have unresolved symbols.

Signed-off-by Andi Kleen <[email protected]>

Index: linux/arch/x86/kernel/rtc.c
===================================================================

arch/x86/kernel/rtc.c +1 -0

@@ -200,3 +200,5 @@ unsigned long long native_read_tsc(void)
 {
 	return __native_read_tsc();
 }
+EXPORT_SYMBOL(native_read_tsc);