meson: add build target feedback to summary

[perigoso]

Add wether firmware and BMDA are being built to the summary output

Detailed description

This just adds a couple entries to meson configuration summary output, telling the user if it's configured to build firmware, and if it's configured to build BMDA, given that the following situations are possible:

• building firmware and BMDA
• building firmware but not BMDA
• building BMDA but not firmware
  Some feedback as to which one we are in felt needed.

Your checklist for this pull request

• I've read the Code of Conduct
• I've read the guidelines for contributing to this repository
• It builds for hardware native (see Building the firmware)
• It builds as BMDA (see Building the BMDA)
• I've tested it to the best of my ability
• My commit messages provide a useful short description of what the commits do

Closing issues

[dragonmux]

This looks good, and seems like a nice addition to the summary output - merging as we can see this works right from the CI builds.