cpufeatures: remove AArch64 crypto target feature (#594)

It was removed from the nightly compiler in this PR:

rust-lang/rust#87729

This crate attempts to provide a 1:1 mapping of CPU feature detection to
rustc's own target features, so this PR accordingly removes it.

Breaking change; will require a minor version bump.

Author: tarcieri

cpufeatures/src/aarch64.rs

@@ -67,7 +67,6 @@ macro_rules! __expand_check_macro {
 #[cfg(target_os = "linux")]
 __expand_check_macro! {
     ("aes",    AES),    // Enable AES support.
-    ("crypto", CRYPTO), // Enable cryptographic instructions.
     ("sha2",   SHA2),   // Enable SHA1 and SHA256 support.
     ("sha3",   SHA3),   // Enable SHA512 and SHA3 support.
 }
@@ -107,9 +106,6 @@ macro_rules! check {
     ("aes") => {
         true
     };
-    ("crypto") => {
-        true
-    };
     ("sha2") => {
         true
     };
@@ -158,9 +154,6 @@ macro_rules! check {
     ("aes") => {
         true
     };
-    ("crypto") => {
-        true
-    };
     ("sha2") => {
         true
     };