Simplify building a firmware for qemu

[dehanj]

Description

• Remove the define NOCONSOLE, add define QEMU_CONSOLE instead.
• Inverse the use of it, add the define to have QEMU debug output in fw. Making it simpler to create a different make target.
• Add a make target qemu_firmware.elf which builds the firmware with QEMU console enabled.
• Also fixing the warning one gets when building with QEMU_CONSOLE defined.

Type of change

Please tick any that are relevant to this PR and remove any that aren't.

• Feature (non breaking change which adds functionality)

Submission checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my changes
• I have tested and verified my changes on target
• My changes are well written and CI is passing
• I have squashed my work to relevant commits and rebased on main for linear history
• I have added a "Co-authored-by: x" if several people contributed, either pair programming or by squashing commits from different authors.
• I have updated the documentation where relevant (readme, dev.tillitis.se etc.)
• QEMU is updated to reflect changes tk1: new name of define to enable HTIF when building firmware qemu#29

[mchack-work]

Updated docs in firmware's README about the new QEMU_CONSOLE.

Updated copyright year in changed files.

Squashed into earlier commits.

Merging.

[mchack-work]

LGTM