ACPI: sysfs: fix doc warnings in device_sysfs.c

Fixes the following W=1 kernel build warning(s):

 drivers/acpi/device_sysfs.c:278: warning: Function parameter or
  member 'dev' not described in 'acpi_device_uevent_modalias'
 drivers/acpi/device_sysfs.c:278: warning: Function parameter or
  member 'env' not described in 'acpi_device_uevent_modalias'
 drivers/acpi/device_sysfs.c:323: warning: Function parameter or
  member 'dev' not described in 'acpi_device_modalias'
 drivers/acpi/device_sysfs.c:323: warning: Function parameter or
  member 'buf' not described in 'acpi_device_modalias'
 drivers/acpi/device_sysfs.c:323: warning: Function parameter or
  member 'size' not described in 'acpi_device_modalias'

Signed-off-by: Baokun Li <libaokun1@huawei.com>
[ rjw: Fix spelling: acpi -> ACPI ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>