Update leh to 0.4 alpha.4

Author: caemor

Cargo.toml

@@ -27,8 +27,7 @@ embedded-hal-mock = { version = "=0.10.0-rc.4", default-features = false, featur
 ] }
 
 [target.'cfg(unix)'.dev-dependencies]
-# linux-embedded-hal = "0.3"
-linux-embedded-hal = { git = "https://github.com/rust-embedded/linux-embedded-hal", rev = "a1fb24103e575615a29c6748cdeff1f0e7a3dae3" }
+linux-embedded-hal = "0.4.0-alpha.4"
 
 [[example]]
 name = "epd1in54_no_graphics"