KVM: VMX: Import some constants of vmcs from IA32 SDM

This patch mainly imports some constants and rename two exist constants
of vmcs according to IA32 SDM.

It also adds two constants to indicate Lock bit and Enable bit in
MSR_IA32_FEATURE_CONTROL, and replace the hardcode _5_ with these two
bits.

Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>