GPU: Remove write to ifpo sysfs node. As part of pa/2288829, this node becomes unsupported. Prevents -ENOTSUPP errors when trying to write to Mali's ifpo sysfs node. Test: Boot to homescreen Bug: 247571932 Change-Id: I0b579728a5b2a4355d648020113dda0592f904aa Signed-off-by: Jeremy Kemp <jeremykemp@google.com>