feat(drs): set up timer control for DRS servo

[t-bre]

Description

• The DRS servo moves one of the parts of the rear wing to change its aerodynamic properties.
• The servo we have is the MG996R.
• The servo is controlled by a pulse of between 1-2ms at a frequency of 50Hz (see datasheet).
• The length of the pulse controls the servo angle.
• For DRS, we want the ability to have the servo in one of two possible (ideally configurable) positions.

Tasks

• Modify VCU.ioc to set up a pin-connected hardware timer for PWM and re-generate code.
• Add a new software module for DRS and write some code to allow the servo position to be controlled.
• Write some kind of testbench.
• Test pulse width using oscilloscope.
• Test control of actual servo on rear wing.

Additional Notes

• When re-generating code, delete the Makefile which gets generated in src - we have our own Makefile in the project root. If it doesn't build, check what was added to the generated Makefile and add it to our one.