thermal: adc-tm: Fix match table description and Makefile

Due to an error in the specification of the multiple compatible strings
in the match table, nodes defined with compatible string "adc-tm5-iio"
failed to probe. Fix this.

Also change the compilation recipe in the Makefile to prevent generation
of multiple kernel modules.

Change-Id: I6cf544b202dfb0773215aeaeae8a12bae5b79dde
Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>