Drivers: hv: vmbus: Define an API to retrieve virtual processor index

As part of cleaning up architecture specific code, define an API
to retrieve the virtual procesor index.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 7cb036d..9457190 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -306,7 +306,7 @@
 	 * of cpuid and Linux' notion of cpuid.
 	 * This array will be indexed using Linux cpuid.
 	 */
-	rdmsrl(HV_X64_MSR_VP_INDEX, vp_index);
+	hv_get_vp_index(vp_index);
 	hv_context.vp_index[cpu] = (u32)vp_index;
 
 	/*