Previously the timeout was set to the same value (1000ms) for all kinds
of commands. In some cases, such as with slow cards, write commands
failed to complete in time.
This change makes command timeouts configurable via sdmmc_host_t
structure, and also makes default timeouts different for ordinary
commands and write commands.
Closes https://github.com/espressif/esp-idf/issues/1093
Ref TW15774.