[Backport v3.7-branch] arch: riscv: stacktrace: fix output without `ra` on the stack top#77048

nashif merged 2 commits intozephyrproject-rtos:v3.7-branchzephyrproject-rtos/zephyr:v3.7-branchfrom

ycsin:pr/v3.7-backport-trace-fixesycsin/zephyr:pr/v3.7-backport-trace-fixesCopy head branch name to clipboard