etnaviv: Implement ICACHE

etnaviv: Implement ICACHE

This patch adds support for large shaders on GC3000. For example the "terrain"
glmark benchmark with a large fragment shader will work after this.

If the GPU supports ICACHE, shaders larger than the available state area will
be uploaded to a bo of their own and instructed to be loaded from memory on
demand. Small shaders will be uploaded in the usual way. This mimics the
behavior of the blob.

On GPUs that don't support ICACHE, this patch should make no difference.

Signed-off-by: Wladimir J. van der Laan <laanwj@gmail.com>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>