Compile error when targeting Android

[black-binary]

When compiling with the target aarch64-android-linux, the bfp module will be enabled.

smoltcp/src/phy/sys/mod.rs

Lines 13 to 14 in 8347da7

	#[cfg(all(feature = "phy-raw_socket", not(target_os = "linux"), unix))]
	pub mod bpf;

And result in a compile error, because the constants below are missing.

smoltcp/src/phy/sys/bpf.rs

Lines 10 to 24 in 8347da7

	/// set interface
	#[cfg(any(target_os = "macos", target_os = "openbsd"))]
	const BIOCSETIF: libc::c_ulong = 0x8020426c;
	/// get buffer length
	#[cfg(any(target_os = "macos", target_os = "openbsd"))]
	const BIOCGBLEN: libc::c_ulong = 0x40044266;
	/// set immediate/nonblocking read
	#[cfg(any(target_os = "macos", target_os = "openbsd"))]
	const BIOCIMMEDIATE: libc::c_ulong = 0x80044270;
	/// set bpf_hdr struct size
	#[cfg(target_os = "macos")]
	const SIZEOF_BPF_HDR: usize = 18;
	/// set bpf_hdr struct size
	#[cfg(target_os = "openbsd")]
	const SIZEOF_BPF_HDR: usize = 24;

I don't need the phy module in my project, in fact. So my workaround is to remove these constants and the code. And I'm not sure how to fix this. As far as I know, Android is based on Linux, so the code of the raw socket in Linux should work in Android.