x86/microcode/AMD: Fix patch level reporting for family 15h

On AMD family 14h, applying microcode patch on the a core (core0)
would also affect the other core (core1) in the same compute
unit. The driver would skip applying the patch on core1, but it
still need to update kernel structures to reflect the proper
patch level.

The current logic is not updating the struct
ucode_cpu_info.cpu_sig.rev of the skipped core. This causes the
/sys/devices/system/cpu/cpu1/microcode/version to report
incorrect patch level as shown below:

  $ grep . cpu?/microcode/version
  cpu0/microcode/version:0x600063d
  cpu1/microcode/version:0x6000626
  cpu2/microcode/version:0x600063d
  cpu3/microcode/version:0x6000626
  cpu4/microcode/version:0x600063d

Signed-off-by: Suravee Suthikulpanit <[email protected]>
Acked-by: Borislav Petkov <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

arch/x86/kernel/microcode_amd.c

@@ -216,6 +216,7 @@ int apply_microcode_amd(int cpu)
 	/* need to apply patch? */
 	if (rev >= mc_amd->hdr.patch_id) {
 		c->microcode = rev;
+		uci->cpu_sig.rev = rev;
 		return 0;
 	}