They are defined in coreboot (MSR_PLATFORM) and the other
one is already defined in msr-index.h.

Let's use those.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>