ACPI: bgrt: take advantage of binary sysfs groups

Attribute groups now can handle binary sysfs attributes, so clean up the
code here by using a binary attribute array.  This saves us the extra
call to create the binary attribute at saves 6 lines overall.

Cc: Len Brown <lenb@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

--
 I can take this in my driver-core tree if someone from ACPI acks it,
 otherwise, feel free to take it through the ACPI trees instead, just
 let me know.

 drivers/acpi/bgrt.c |   26 ++++++++++----------------
 1 file changed, 10 insertions(+), 16 deletions(-)