scsi: ufs: core: Improve documentation in include/ufs/ufshci.h

Make it easier to find the sections in the UFSHCI standard where these
constants come from.

Signed-off-by: Bart Van Assche <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Martin K. Petersen <[e-mail]>

include/ufs/ufshci.h

···
 };
 
 enum {
+	/* Submission Queue (SQ) Configuration Registers */
 	REG_SQATTR		= 0x0,
 	REG_SQLBA		= 0x4,
 	REG_SQUBA		= 0x8,
 	REG_SQDAO		= 0xC,
 	REG_SQISAO		= 0x10,
 
+	/* Completion Queue (CQ) Configuration Registers */
 	REG_CQATTR		= 0x20,
 	REG_CQLBA		= 0x24,
 	REG_CQUBA		= 0x28,
···
 	REG_CQISAO		= 0x30,
 };
 
+/* Operation and Runtime Registers - Submission Queues and Completion Queues */
 enum {
 	REG_SQHP		= 0x0,
 	REG_SQTP		= 0x4,