sdcard: Disable SEND_IF_COND (CMD8) for Spec v1

CMD8 is "Reserved" in Spec v1.10.

Spec v2.00 introduces the SEND_IF_COND command:

  6.4.1 Power Up

    CMD8 is newly added in the Physical Layer Specification Version
    2.00 to support multiple voltage ranges and used to check whether
    the card supports supplied voltage. The version 2.00 or later host
    shall issue CMD8 and verify voltage before card initialization.
    The host that does not support CMD8 shall supply high voltage range.

Message-Id: 201204252110.20873.paul@codesourcery.com
Signed-off-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20180607180641.874-5-f4bug@amsat.org
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

hw/sd/sd.c

@@ -1018,7 +1018,9 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
         break;
 
     case 8:	/* CMD8:   SEND_IF_COND */
-        /* Physical Layer Specification Version 2.00 command */
+        if (sd->spec_version < SD_PHY_SPECv2_00_VERS) {
+            break;
+        }
         if (sd->state != sd_idle_state) {
             break;
         }