In psmprobe(), we set the initial `syncmask` to the vendor default value
if the `PSM_CONFIG_NOCHECKSYNC` bit is unset. However, we currently only
set it for the Elantech touchpad later in psmattach(), thus `syncmask`
is always configured.
Now, we check `PSM_CONFIG_NOCHECKSYNC` and skip sync check if it is set.
This fixes Elantech touchpad support for units which have `hascrc` set.
To clarify that, when we log the `syncmask` and `syncbits` fields, also
mention if they are actually used.
Finally, when we set `PSM_CONFIG_NOCHECKSYNC`, clear `PSM_NEED_SYNCBITS`
flag.
PR: 225338
MFC after: 1 week
9402bd96df