* Add missing DREQ_s
* store actual clock frequency in clock_configure (fixes#368)
* use dma DREQ values defined in dreqs/dma.h
* Fix hw_is_claimed, and add xxx_is_claimed APIs
* Add some PIO irq helper methods
* Add DMA channel IRQ status getter and clear methods
* Implement the correct PIO IRQ status/clear methods (good to have methods here as the h/w interrupt registers are super confusing)
* fix pico_multicore dependencies
* add missing wrapper func __aeabi_f2d
* Further DMA/PIO IRQ API cleanup (and review fixes)
* add PICO_INT64_OPS_IN_RAM flag
* - fix interp_claim_lane (in case of interp1 and lane==1 bit was 0b11 instead of 0b1000)
- added missing function interp_unclaim_lane_mask
* - interp_hw_save_t are not I/O registers
In C, func() is a function taking an unspecified number of arguments,
vs func(void) a function taking no arguments. In C++ both forms indicate
"no arguments."
Update these headers to use the (void) form, which is correct in both
languages and avoids complaints when -Wstrict-prototypes is specified.
