add spi_display with mipidsi example for rp pico

[Georges760]

This PR is another example of rp spi display but using the generic mipidsi crate (https://github.com/almindor/mipidsi).

I used the GC9A01 round AMOLED display as I have thi one on hand.

Unfortunately the GC9A01 model has been added recently to mipidsi and is not in v0.7.1 tag (latest). So I use the git version for now.