Revert "arch/riscv: Get current CPU properly instead of assuming single CPU"

This reverts commit 8686ab54727c3d99d41a5de663656522557cf241.

The purpose of this commit will be reintroduced later on top of
a cleaner codebase.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2 files changed