scsi: ufs: pltfrm: Add DT support to limit HS gear and gear rate

Introduce parsing of 'limit-hs-gear' and 'limit-gear-rate' device tree
properties to restrict high-speed gear and rate during initialization.

This is useful in cases where the customer board may have signal
integrity, clock configuration or layout issues that prevent reliable
operation at higher gears. Such limitations are especially critical in
those platforms, where stability is prioritized over peak performance.

Co-developed-by: Nitin Rawat <quic_nitirawa@quicinc.com>
Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
Signed-off-by: Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>