sdcard: Disable CMD19/CMD23 for Spec v2

These commands got introduced by Spec v3
(see 0c3fb03f and 4481bbc7).
Signed-off-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20180607180641.874-7-f4bug@amsat.org
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

hw/sd/sd.c

@@ -1179,6 +1179,9 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
         break;
 
     case 19:    /* CMD19: SEND_TUNING_BLOCK (SD) */
+        if (sd->spec_version < SD_PHY_SPECv3_01_VERS) {
+            break;
+        }
         if (sd->state == sd_transfer_state) {
             sd->state = sd_sendingdata_state;
             sd->data_offset = 0;
@@ -1187,6 +1190,9 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
         break;
 
     case 23:    /* CMD23: SET_BLOCK_COUNT */
+        if (sd->spec_version < SD_PHY_SPECv3_01_VERS) {
+            break;
+        }
         switch (sd->state) {
         case sd_transfer_state:
             sd->multi_blk_cnt = req.arg;