smbios: Don't report unknown CPU speed (fix SVVP regression)

SVVP requires processor speed on Type 4 structures to not be unknown.
This was fixed in SeaBIOS 0.5.0 (in 2009), but the bug was reintroduced
in QEMU 2.1.

Revert to old behavior and report CPU speed as 2000 MHz instead of
unknown.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>

hw/i386/smbios.c

@@ -618,8 +618,9 @@ static void smbios_build_type_4_table(unsigned instance)
     SMBIOS_TABLE_SET_STR(4, processor_version_str, type4.version);
     t->voltage = 0;
     t->external_clock = cpu_to_le16(0); /* Unknown */
-    t->max_speed = cpu_to_le16(0); /* Unknown */
-    t->current_speed = cpu_to_le16(0); /* Unknown */
+    /* SVVP requires max_speed and current_speed to not be unknown. */
+    t->max_speed = cpu_to_le16(2000); /* 2000 MHz */
+    t->current_speed = cpu_to_le16(2000); /* 2000 MHz */
     t->status = 0x41; /* Socket populated, CPU enabled */
     t->processor_upgrade = 0x01; /* Other */
     t->l1_cache_handle = cpu_to_le16(0xFFFF); /* N/A */