This patch provides support for enabling the kdump service on riscv. After
starting the kdump service, the kdump kernel can be successfully loaded,
and after triggering a kernel crash, the kdump kernel can be started
normally and the vmcore can be captured.
Due to some issues with initrd in kexec-tools, avoid it first to provide
basic riscv architecture kdump support. Tested in openeuler riscv qemu,
and can also pass Mugen testing.
Signed-off-by: Mingzheng Xing <xingmingzheng@iscas.ac.cn>
(cherry picked from commit 7033d5da29de3ac009d36a9e5e516aaa6d58712d)
