Add mkl support for matrix multiply. (#86)

* Fix some rebase issues.

* Use mkl instead.

* Use mkl in bert.

* Add the optional mkl feature.

* Conditional compilation based on the mkl feature.

* Add more mkl support.

candle-examples/examples/whisper/main.rs

@@ -6,6 +6,9 @@
 // - Batch size greater than 1.
 // - More token filters (SuppressBlanks, ApplyTimestampRules).
 
+#[cfg(feature = "mkl")]
+extern crate intel_mkl_src;
+
 use anyhow::{Error as E, Result};
 use candle::{DType, Device, Tensor};
 use candle_hub::{api::Api, Repo, RepoType};