x86: Remove double declaration of MSR_P6_EVNTSEL0 and MSR_P6_EVNTSEL1

MSR_P6_EVNTSEL0 and MSR_P6_EVNTSEL1 is already declared in msr-index.h.

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
LKML-Reference: <1246450778.6940.8.camel@hpdv5.satnam>
Signed-off-by: Ingo Molnar <mingo@elte.hu>