UPSTREAM: scsi: ufs: Add trace event for UIC commands

Use the ftrace infrastructure to conditionally trace UFS UIC command
events.

New trace event "ufshcd_uic_command" is created, which samples the
following UFS UIC command data:

 - Device name
 - Optional identification string
 - UIC command opcode
 - UIC command argument1
 - UIC command argument2
 - UIC command argement3

Usage:
	echo 1 > /sys/kernel/debug/tracing/events/ufs/enable
	cat /sys/kernel/debug/tracing/trace_pipe

Link: https://lore.kernel.org/r/20200615072235.23042-3-stanley.chu@mediatek.com


Acked-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Bug: 151050916
(cherry picked from commit aa5c697988b4c7e1077de1e2eb2298114d531736)
Change-Id: I23652110c51d7cd04f9e9c565f67654325e11e9d
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>