FROMLIST: scsi: ufs: Make HCM parameter configurable

We can make use of this commit, to elaborate some more of the host
control mode logic, explaining what role play each and every variable.

While at it, allow those parameters to be configurable.

Bug: 183467926
Bug: 170940265
Bug: 183454255

Link: https://lore.kernel.org/lkml/20210607061401.58884-13-avri.altman@wdc.com/


Signed-off-by: Avri Altman <avri.altman@wdc.com>
Change-Id: Ib05c6643c69504b8d9442b0024cfe1b0b687a4ce