some fixes to VMX:

some fixes to VMX:
1) enable ACPI in VMXAssist by default.
2) do nothing when emulating wbinvd instruction in VMXAssist.
3) use MACRO in cpu number setting/getting code.
4) remove useless parameter flags from xc_vmx_build.
5) remove usage of dsi.v_start in xc_vmx_build when not handling
vmxloader elf.
6) unmap shared_page_va when destroy VMX domain.
7) change virtual_platform_def to vmx_platform.
8) remove useless code in vmx_setup_platform.
9) change parameter of vmx_setup_platform from vcpu to domain.
10) in xen HV, vmx domain get domain processor number from the reserved
E820 area.
11) in domain.c, don't define some functions when on i386 platform or no
CONFIG_VMX.
Also removed some ugly tailing space.

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