thermal: qpnp-temp-alarm: Fix compilation error

Checks against NULL for "pdev", "pdev->dev" and "of_node" are not
necessary as these are not expected to be NULL in the probe. Hence
remove these checks. This addresses the compilation issue as well.

Change-Id: Ifd9d8910dc81edaee1f3998e5d9f9e463aab65d5
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>