mmc: tmio: Use devm_mmc_alloc_host() helper

mmc: tmio: Use devm_mmc_alloc_host() helper

Use new function devm_mmc_alloc_host() to simplify the code.

Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Link: https://lore.kernel.org/r/d7d9120fc1ca2eb014cda4e481af5add05be0bf6.1748933789.git.zhoubinbin@loongson.cn
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>