fix register name and description in FFT

Remove work-around for pcrel issue

readme: fix link

With rust-lang/rust#62281, rust compiles in mcmodel=medium mode
by default and this work-around is no longer needed.

regenerate with 0.16.1

Make sure PLIC targets becomes an array

Add a `_reserved` element to make sure svd2rust generates the PLIC targets
array as an array.

Add interrupts for all peripherals

Using svd2rust tag v0.16.0

Use the same names and numbers as in `lib/drivers/include/plic.h` in the
SDK.

https://github.com/djmcgill/form/issues/12

DMAC

KPU

FFT

Also regenerate rust files.

Info from `src/lib/drivers/include/fft.h` `lib/drivers/fft.c`

APU