wil6210: add sysfs for thermal throttling configuration

New sysfs entry "thermal_throttling" can be used to configure
boundaries of each thermal zone.
There are two sets of configurations, one for baseband and one for rf.
Each config contains 3 thermal zones: high, max, critical.
Each zone has high and low temperature set points (in Celsius).
The format for writing is a series of 12 unsigned bytes:
<bb_zone1_high> <bb_zone1_low> <bb_zone2_high> <bb_zone2_low> \
<bb_zone3_high> <bb_zone3_low> <rf_zone1_high> <rf_zone1_low> \
<rf_zone2_high> <rf_zone2_low> <rf_zone3_high> <rf_zone3_low>
To disable thermal throttling for baseband or for rf, use 0 for all
its six set points.

Change-Id: I6990cc0e8375905e4d95e2533d2188be785d9f4a
Signed-off-by: Dedy Lansky <dlansky@codeaurora.org>
[ailizaro@codeaurora.org: trivial conflict fixes]
Signed-off-by: Alexei Avshalom Lazar <ailizaro@codeaurora.org>
[liord@codeaurora.org: fix merge conflicts]
Signed-off-by: Lior David <liord@codeaurora.org>