x86/platform/uv: Fix UV4 hub revision adjustment

Currently, UV4 is incorrectly identified as UV4A and UV4A as UV5. Hub
chip starts with revision 1, fix it.

 [ bp: Massage commit message. ]

Fixes: 647128f1 ("x86/platform/uv: Update UV MMRs for UV5")
Signed-off-by: Mike Travis <mike.travis@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Steve Wahl <steve.wahl@hpe.com>
Acked-by: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Link: https://lkml.kernel.org/r/20201203152252.371199-1-mike.travis@hpe.com

arch/x86/kernel/apic/x2apic_uv_x.c

@@ -161,7 +161,7 @@ static int __init early_set_hub_type(void)
 	/* UV4/4A only have a revision difference */
 	case UV4_HUB_PART_NUMBER:
 		uv_min_hub_revision_id = node_id.s.revision
-					 + UV4_HUB_REVISION_BASE;
+					 + UV4_HUB_REVISION_BASE - 1;
 		uv_hub_type_set(UV4);
 		if (uv_min_hub_revision_id == UV4A_HUB_REVISION_BASE)
 			uv_hub_type_set(UV4|UV4A);