mmc: tegra: don't use periph_id in pad_init_mmc()

The MMC driver will soon be converted to use standard clock/reset APIs,
and so the periph_id field in the MMC device priv struct will disappear.
Rework the implementation of pad_init_mmc() to rely on this; using the
device register address is a much more direct test anyway.

Cc: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>

drivers/mmc/tegra_mmc.c

@@ -451,14 +451,13 @@ static void tegra_mmc_set_ios(struct mmc *mmc)
 static void pad_init_mmc(struct mmc_host *host)
 {
 #if defined(CONFIG_TEGRA30)
-	enum periph_id id = host->mmc_id;
 	u32 val;
 
-	debug("%s: sdmmc address = %08x, id = %d\n", __func__,
-	      (unsigned int)host->reg, id);
+	debug("%s: sdmmc address = %08x\n", __func__, (unsigned int)host->reg);
 
 	/* Set the pad drive strength for SDMMC1 or 3 only */
-	if (id != PERIPH_ID_SDMMC1 && id != PERIPH_ID_SDMMC3) {
+	if (host->reg != (void *)0x78000000 &&
+	    host->reg != (void *)0x78000400) {
 		debug("%s: settings are only valid for SDMMC1/SDMMC3!\n",
 		      __func__);
 		return;