accel/qaic: Add DMA Bridge Channel(DBC) sysfs and uevents

accel/qaic: Add DMA Bridge Channel(DBC) sysfs and uevents

Expose sysfs files for each DBC representing the current state of that DBC.
For example, sysfs for DBC ID 0 and accel minor number 0 looks like this,

/sys/class/accel/accel0/dbc0_state

Following are the states and their corresponding values,
DBC_STATE_IDLE (0)
DBC_STATE_ASSIGNED (1)
DBC_STATE_BEFORE_SHUTDOWN (2)
DBC_STATE_AFTER_SHUTDOWN (3)
DBC_STATE_BEFORE_POWER_UP (4)
DBC_STATE_AFTER_POWER_UP (5)

Signed-off-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@quicinc.com>
Signed-off-by: Youssef Samir <youssef.abdulrahman@oss.qualcomm.com>
Signed-off-by: Zack McKevitt <zachary.mckevitt@oss.qualcomm.com>
Reviewed-by: Jeff Hugo <jeff.hugo@oss.qualcomm.com>
Signed-off-by: Jeff Hugo <jeff.hugo@oss.qualcomm.com>
Link: https://patch.msgid.link/20251031174059.2814445-2-zachary.mckevitt@oss.qualcomm.com