Add a loop around SDL_hid_read() in the Steam Deck HIDAPI driver as it
is done in other HIDAPI drivers. This loop reads data from the device and
processes it until the input buffer is empty which ensures that clients
always get the latest data.
This fixes an input latency issue if the application polls the events
slower than the hardware generates them.
This makes it easier for games that don't use the gamepad API to handle D-Pad navigation, and is consistent with many other non-HIDAPI mappings.
Fixes https://github.com/libsdl-org/SDL/issues/8754
