Add a dedicated NSH tool for testing and interacting with analog
comparator devices (/dev/comp*). Supports reading comparator output
state, enabling/disabling via IOCTL, and performing an automated voltage
ramp sweep using a DAC device when available.
Assisted-by: Gemini:gemini-2.5-pro
Signed-off-by: Daniel P. Carvalho <danieloak@gmail.com>
