mmc: core: add devm_mmc_alloc_host

Add a device-managed version of mmc_alloc_host().

The argument order is reversed compared to mmc_alloc_host() because
device-managed functions typically have the device argument first.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/6d8f9fdc-7c9e-8e4f-e6ef-5470b971c74e@gmail.com


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>