ACPI: dock: fix some coding style issues

Fix some coding style issues reported by checkpatch.pl, including
following types:

WARNING: Missing a blank line after declarations
ERROR: spaces required around that ':'
WARNING: Statements should start on a tabstop

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>