Optimize device boot time

[TychoVrahe]

This PR optimizes boot times with few improvements:

• on T3T1/STM32U5, hash processor is used to calculate image hash, the hash algorithm is switched to SHA256
• checking of empty area after fw image is optimized by comparing words rather than bytes
• I2C initialization on U5 is sped up by using static value for timing register
• touch is initialized at the start of bootloader, so that the waiting time is utilized to check fw image. (see Bootloader: calculate image hashes while waiting for touch to come up #3429 )
• unnecessary delays are removed from touch driver initialization
• the period for checking touch for bootloader entry is shortened from 200ms to 10ms, which is sufficient as long as the user is swiping before this check, which i think is the point anyway. It might change the UX of entering the bootloader a bit though. Users should not need to enter bootloader that often now that we have interaction less fw update, but for TT we might want to keep the original delay not to mess with users muscle memory

[matejcik]

not sure what the vendor header changes are doing here

otherwise ACK code-wise but not approving yet, I would like more people to play with the shortened bootloader delay

also @cepetr please review too

[TychoVrahe]

The vendor headers are regenerated for U5 models because we now use SHA256 to calculate their hash (which is then signed). Unsafe prod signed vendor headers are removed because they are no longer valid after the algo change.

[TychoVrahe]

added a fix with dma interrupt priority setting, and dma channel security configuration (now allowed in unprivileged mode)

c2beaa4