fasolo, klecker: blacklist acpi power meter. rt#6974
workaround dmesg noisy errors, which are safe to ignore:
```
[
3723410.864219] ACPI Error: SMBus/IPMI/GenericSerialBus write requires Buffer of length 66, found length 32 (
20160831/exfield-427)
[
3723410.890212] ACPI Error: Method parse/execution failed [\_SB.PMI0._PMM] (Node
ffffa0e2fe877280), AE_AML_BUFFER_LIMIT (
20160831/psparse-543)
[
3723410.920171] ACPI Exception: AE_AML_BUFFER_LIMIT, Evaluating _PMM (
20160831/power_meter-338)
```
Signed-off-by: Héctor Orón Martínez <zumbi@debian.org>