Drivers: hv: vmbus: Remove x86 MSR refs in arch independent code

In architecture independent code for manipulating Hyper-V synthetic timers
and synthetic interrupts, pass in an ordinal number identifying the timer
or interrupt, rather than an actual MSR register address.  Then in
x86/x64 specific code, map the ordinal number to the appropriate MSR.
This change facilitates the introduction of an ARM64 version of Hyper-V,
which uses the same synthetic timers and interrupts, but a different
mechanism for accessing them.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>