[BUG] Incorrect Telemetry Size using CppFromXTCETelemetry.py

[CasperBroekhuizen]

Generating Telemetry files will have an incorrect TELEMETRY_SIZE define, the last variable is not included in the calculation of the size.

• EPS telemetry out of range? OBC_FlightSoftware#5
• EPS telemetry out of range? EPS_FlightSoftware#15