mmc: sdhci-cadence: Enable software tuning for both SD and eMMC interfaces

mmc: sdhci-cadence: Enable software tuning for both SD and eMMC interfaces

Remove interface type restrictions in sdhci_cdns_execute_tuning() to
enable software tuning for both SD and eMMC devices. The previous
assumption that SD timing should be handled by SDHCI core is incorrect
based on the actual function assignment logic.

The execute_tuning function is assigned based on MMC_SUPPORTS_TUNING
config, which is enabled by both MMC_UHS_SUPPORT and MMC_HS200_SUPPORT.

Changes:
Remove IS_MMC() check that restricted tuning to eMMC only
Remove opcode validation limited to MMC_CMD_SEND_TUNING_BLOCK_HS200

Signed-off-by: Tanmay Kathpalia <tanmay.kathpalia@altera.com>
Reviewed-by: Balsundar Ponnusamy <balsundar.ponnusamy@altera.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>