x86: hypervisor - fix sparse warnings

Impact: fix sparse build warning

Fix the following sparse warnings:

  arch/x86/kernel/cpu/hypervisor.c:37:15: warning: symbol
  'get_hypervisor_tsc_freq' was not declared. Should it be static?
  arch/x86/kernel/cpu/hypervisor.c:53:16: warning: symbol
  'init_hypervisor' was not declared. Should it be static?
Signed-off-by: NHannes Eder <hannes@hanneseder.net>
Cc: "Alok N Kataria" <akataria@vmware.com>
Cc: "Dan Hecht" <dhecht@vmware.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/cpu/hypervisor.c

@@ -23,6 +23,7 @@
 
 #include <asm/processor.h>
 #include <asm/vmware.h>
+#include <asm/hypervisor.h>
 
 static inline void __cpuinit
 detect_hypervisor_vendor(struct cpuinfo_x86 *c)