x86/hyperv: Expand definition of struct hv_vp_assist_page

x86/hyperv: Expand definition of struct hv_vp_assist_page

The struct hv_vp_assist_page has 24 bytes which is defined as u64[3],
expand that to expose vtl_entry_reason, vtl_ret_x64rax and vtl_ret_x64rcx
field. vtl_entry_reason is updated by hypervisor for the entry reason as
to why the VTL was entered on the virtual processor.

Guest updates the vtl_ret_* fields to provide the register values to
restore on VTL return. The specific register values that are restored
which will be updated on vtl_ret_x64rax and vtl_ret_x64rcx.

Also added the missing fields for synthetic_time_unhalted_timer_expired,
virtualization_fault_information and intercept_message.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: <anrayabh@linux.microsoft.com>
Link: https://lore.kernel.org/r/1667587123-31645-1-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>