IOMMU: imply "verbose" from "debug"

I think that generally enabling debugging code without also enabling
verbose output is rather pointless; if someone really wants this, they
can always pass e.g. "iommu=debug,no-verbose".

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -92,7 +92,11 @@ static void __init parse_iommu_param(cha
         else if ( !strcmp(s, "intremap") )
             iommu_intremap = val;
         else if ( !strcmp(s, "debug") )
+        {
             iommu_debug = val;
+            if ( val )
+                iommu_verbose = 1;
+        }
         else if ( !strcmp(s, "amd-iommu-perdev-intremap") )
             amd_iommu_perdev_intremap = val;
         else if ( !strcmp(s, "dom0-passthrough") )