x86/tsc: Convert to use x86_match_cpu() and INTEL_CPU_FAM6()

Move the code to use recently introduced INTEL_CPU_FAM6() macro and
drop custom version of x86_match_cpu() function.

No functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Link: https://lkml.kernel.org/r/20180629193113.84425-3-andriy.shevchenko@linux.intel.com