Set 192MHz min freq as default

Signed-off-by: kecinzer <kecinzer@gmail.com>
Add overclock capabilities

Added five new frequency steps up to 2 GHz.

Signed-off-by: kecinzer <kecinzer@gmail.com>
Simple GPU overclocking to 450MHz

Simple replace 400 to 450MHz slot.

Signed-off-by: kecinzer <kecinzer@gmail.com>