powerpc/ps3: Fix lv1_gpu_attribute hcall

The lv1_gpu_attribute hcall takes three, not five input
arguments.  Adjust the lv1 hcall table and all calls.

Signed-off-by: Geoff Levand <geoff@infradead.org>
CC: Takashi Iwai <tiwai@suse.de>
Acked-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>