Revert "nicki: gpu: overclock to 533Mhz"

This reverts commit cee226ad8f3d8515c9aef59fa564540538e18fbb.
Revert "OC to 1.7GHZ"

This reverts commit 6d2d127cc03ef26123f8ecebd257b91312300f83.
Revert "OC to 1.7GHZ"

This reverts commit 299436502e726455124e381090631492ec81b099.