Clean up some VMX IO handler code:

Clean up some VMX IO handler code:
1. Clean up some definitions.
2. change d to v, if it means vcpu.
3. remove some tailing spaces.

TODO:
split current VMX IO handler list to 2, one for port IO,
and the other for MMIO.

Signed-off-by: Xin Li <xin.b.li@intel.com>