ata: ahci_tegra: Convert to devm_platform_ioremap_resource()

Use devm_platform_ioremap_resource() to simplify code.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>