Hi Paolo,
Thank you for your interest in NXP Semiconductor products and the opportunity to serve you.
Grey-shaded blocks show peripherals that can provide hardware triggers for DMA transfers or have DMA request lines as the Fig 1 illustrates.

Fig 1
DMA can be permitted to access to the HS GPIO definitely, and it is nothing related with the DMA requests or triggers. Hope it helps.
Have a great day,
Ping
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