Add node to set and show programming mode for TPDM DSB subunit.
Once the DSB programming mode is set, it will be written to the
register DSB_CR.
Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/1695882586-10306-9-git-send-email-quic_taozha@quicinc.com