More RAM for Python heap, audio samples and graphics

[bwhitman]

Tulip CC ships with 8 megabytes PSRAM. Mostly due to the display, we need to store a copy of the firmware (3 MB) as a cache, which only leaves us with 5MB left. Then we use 2MB for Python heap, and about 1MB for the frambuffer(s). That leaves us about 1.5MB-2MB for "everything else" - samples, graphics, anything you malloc.

32MB PSRAM chips are now getting to be more widely available. Assuming it's a drop in or easy package, we should move up to that.

[bwhitman]

A note here, with AMYchip involved, the firmware size on the tulip chip will go down significantly (say, to 1MB) and we'll have 6MB available for heap and outside Python ram if we move AMY out of Tulip. (and we can use AMYchip ram for samples)