wil6210: fix temperature debugfs

For negative temperatures, "temp" debugfs is showing wrong values.
Use signed types so proper calculations is done for sub zero
temperatures.

Change-Id: Ie44b2f679ccca6bb80b5fd57a9b3eb2ed38d4798
Signed-off-by: Dedy Lansky <dlansky@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Git-commit: 6d9eb7ebae3d7e951bc0999235ae7028eb4cae4f
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git


Signed-off-by: Maya Erez <merez@codeaurora.org>