regarding folder common/espressif

Currently we have `arch/risc-v/src/commmon/espressif` which holds `espressif` specific things only.

I am wondering if it can be moved out of the common folder of all RiscV chips? probably to a folder like `arch/risc-v/src/espressif`?

This feels more in line what we have done for `arch/arm`. This also makes its changes only be checked against espressif chips later when our CI is smarter.