Add support for enabling multiple disk interfaces (Flash, RAM)
simultaneously in Zephyr by introducing a simple disk interface
framework where we can register multiple disks which would
interface with different storage devices. This would enable us
to have multiple instances of FATFS in Zephyr.
Add support for mass storage drive disk name which will be
used as an argument when calling the disk interface API's.
Enable multiple volumes support configuration in
ELM FAT library.
Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>