QEMU side has already imported pvpanic.h from linux, remove bit
definitions from include/hw/misc/pvpanic.h, and use
include/standard-headers/linux/pvpanic.h instead.
Also minor changes for PVPANIC_CRASHLOADED -> PVPANIC_CRASH_LOADED.

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Message-Id: <20220221122717.1371010-2-pizhenwei@bytedance.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>