Tegra30: mmc: Add Tegra30 SDMMC compatible entry to fdtdec & driver

Tegra30 SD/MMC controller differs enough from Tegra20 that it
needs its own entry in the compat_names/compat_id tables and in
the Tegra MMC driver.

Signed-off-by: Tom Warren <twarren@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>