glsl/linker: remove ubo explicit binding handling

glsl/linker: remove ubo explicit binding handling

This is already handled at link_uniform_blocks, specifically at
process_block_array_leaf.

Additionally, this code was not handling correctly arrays of
arrays. When creating the name of the block to set the binding, it
only took into account the first level, so any attempt to set a
explicit binding on a array of array ubo would trigger an assertion.

Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>