KVM: SVM: Remove KVM specific defines for MSR_EFER

This patch removes the KVM specific defines for MSR_EFER that were being used
in the svm support file and migrates all references to use instead the ones
from the kernel headers that are used everywhere else and that have the same
values.

Signed-off-by: Carlo Marcelo Arenas Belon <carenas@sajinet.com.pe>
Signed-off-by: Avi Kivity <avi@qumranet.com>