scsi: ufs: core: Enforce minimum PM level for sysfs configuration

scsi: ufs: core: Enforce minimum PM level for sysfs configuration

Some UFS platforms only support a limited subset of power levels.
Currently, the sysfs interface allows users to set any PM level without
validating the minimum supported value. If an unsupported level is
selected, suspend may fail.

Introduce an pm_lvl_min field in the ufs_hba structure and use it to
clamp the PM level requested via sysfs so that only supported levels are
accepted. Platforms that require a minimum PM level can set this field
during probe.

Signed-off-by: Ram Kumar Dwivedi <ram.dwivedi@oss.qualcomm.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20260113080046.284089-4-ram.dwivedi@oss.qualcomm.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>