scsi: ufs: core: Remove unused function declaration

Commit 2468da61

 ("scsi: ufs: core: mcq: Configure operation and runtime
interface") added ufshcd_mcq_select_mcq_mode(), but it's not used
anywhere. So remove it.

Signed-off-by: Keoseong Park <keosung.park@samsung.com>
Link: https://lore.kernel.org/r/20230627012931epcms2p76f458e0b2ce8a591b56bbcc6a2f1a3bb@epcms2p7


Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>