systemd/src/shared/linux

The files in this directory are copied from kernel-5.2, and the following modifications are applied:
- auto_dev-ioctl.h: set AUTOFS_DEV_IOCTL_VERSION_MINOR to 0
- auto_dev-ioctl.h: define AUTOFS_IOCTL if not defined
- bpf_insn.h: This is imported from samples/bpf/bpf_insn.h
- bpf_insn.h: BPF_JMP_A() macro is also imported from include/linux/filter.h
- dm-ioctl.h: set DM_VERSION_MINOR to 27
- ethtool.h: define __KERNEL_DIV_ROUND_UP if not defined
- ethtool.h: add casts in ethtool_cmd_speed()