[SeaBIOS] [PATCH]: enable USE_PLATFORM_CLOCK bit in FADT flags

[Kevin O'Connor]

On Tue, Jul 17, 2012 at 02:18:00PM -0300, Marcelo Tosatti wrote:
> 
> Enable bit 15 (USE_PLATFORM_CLOCK) of FADT flags field so that
> older Windows guests do not make use of the TSC for timestamping. 

I fixed up and committed this patch.  But after I committed it, I
realized it reverted Gleb's "Drop FIX_RTC flag from FADT" patch
(c7be281b).  Gleb, if you can you confirm c7be281b is still valid I'll
put it back in.

-Kevin