mmc: kconfig: replace FAULT_INJECTION with FAULT_INJECTION_DEBUG_FS
Fault-injection capability for MMC IO uses debugfs entries to configure
the attributes.
FAULT_INJECTION_DEBUG_FS must be enabled to use FAIL_MMC_REQUEST.
Replace FAULT_INJECTION with FAULT_INJECTION_DEBUG_FS.
Also remove 'select DEBUG_FS' since FAULT_INJECTION_DEBUG_FS depends on
it.