light and fan. together but separate
To do what you ask:

Disconnect the supply for the fan switch - wire-nut and tape it (it will be going no-where.) 

If it's a jumper from the light switch supply, just remove the jumper. If the light switch is supplied by a jumper from the fan, remove the jumper and move the supply to the light switch. 

Put a pigtail on the light switch switched hot, and connect the light (which was connected to the switched hot), and the supply for the fan switch to that pigtail.

... but my comment is probably a better approach to take.