ACPI: fix acpi_driver.name usage

It was erroneously used as a description rather than a name.

ie. turn this:

lenb@se7525gp2:/sys> ls bus/acpi/drivers
ACPI AC Adapter Driver  ACPI Embedded Controller Driver  ACPI Power Resource Driver
ACPI Battery Driver     ACPI Fan Driver                  ACPI Processor Driver
ACPI Button Driver      ACPI PCI Interrupt Link Driver   ACPI Thermal Zone Driver
ACPI container driver   ACPI PCI Root Bridge Driver      hpet

into this:

lenb@se7525gp2:~> ls /sys/bus/acpi/drivers
ac  battery  button  container  ec  fan  hpet  pci_link  pci_root  power  processor  thermal

Signed-off-by: Len Brown <len.brown@intel.com>