Fix STM32F7 ITCM Flash alias map

[ALTracer]

Detailed description

• Not a new feature.
• The existing problem is BMP/GDB Load failed for STM32F7 binaries linked to 0x0200_0000 ITCM flash bigger than 64 KiB.
• This PR solves it by extending/copying AXIM flash map to ITCM flash alias map.

Tested on STM32F722RE with BMDA/blackpill-f411ce to allow loading 512 KiB binaries (erase, write, verify, in-firmware check). Testers with F76x/F77x (like STM32F777) are otherwise welcome.

I've changed the order of first bank stm32f4_add_flash() calls here, maybe it's unwanted. But the following code block will also want to append to ITCM dual-bank sectors. If mixed order in-BMP is a problem, please state so. Another worry is this will interact with future blank_check feature, forcing it to walk entire NVM twice. I'd like to treat this separately by tracking e.g. some "is-alias" flag, also applicable to OTP pages (of G0).
Like in PR2075, please clarify whether refman references are mandatory there or here.

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

Closes #2006.