drivers: thermal: remove c99 comments

ERROR: do not use C99 // comments.
c99 comments has been removed in intel_pch_thermal.c

Signed-off-by: Hema prathaban <hemaklnce@gmail.com>
Merge branch 'hema-pch-thermal' of github.com:hemaprathaban/thermal into hemalocal

 local pch copy