Revert "max8998_charger: Include linux/module.h just once"

This reverts commit 0c7b5558ecc0a508bb7199776afbf18279595539.

linux-next has the following patch:

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commit 13ae246d
Author: Paul Gortmaker <paul.gortmaker@windriver.com>
Date:   Sun Jan 29 15:44:45 2012 -0500

    includecheck: delete any duplicate instances of module.h
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It removes the other instance of include/module.h in this
driver, and so both gets removed. This makes max8998 driver
non-buildable.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>