Use spidev 0.6.1 instead of 0.7.0 to avoid breaking change

Author: jannic

Cargo.toml

@@ -31,7 +31,7 @@ sysfs_gpio = { version = "0.6.1", optional = true }
 i2cdev = { version = "0.6.0", optional = true }
 nb = "1"
 serialport = { version = "4.2.0", default-features = false, optional = true }
-spidev = { version = "0.7.0", optional = true, git = "https://github.com/rust-embedded/rust-spidev.git", rev = "refs/pull/49/head" }
+spidev = { version = "0.6.1", optional = true }
 nix = { version = "0.27.1", optional = true }
 tokio = { version = "1", default-features = false, optional = true }