redhat: Add support for risc-v

This MR was created in order to get Fedora config changes for risc-v (which are currently being maintained downstream here: http://fedora.riscv.rocks:3000/rpms/kernel/src/branch/main-riscv64) into kernel-ark. This will help us with our goal of making risc-v a supported architecture for Fedora and RHEL. This kernel was tested (at least boot) by at least a couple folks on physical hardware.

Closes #162 (closed)

Signed-off-by: Isaiah Stapleton istaplet@redhat.com