Too much whitespace in the RI5CY block diagram

Hi Davide. I just merged your pull-request on this repo (https://github.com/openhwgroup/core-v-docs/pull/2#issue-348592699). From a revision-control perspective it went perfectly - thanks!

The block diagram has a lot of white-space that pushes the text off the bottom of the screen. The text is still there, but it is pushed off screen. Can the white-space be cut off the block diagram?