crypto/fsl - Add progressive hashing support using hardware acceleration.

Currently only normal hashing is supported using hardware acceleration.
Added support for progressive hashing using hardware.

Signed-off-by: Ruchika Gupta <ruchika.gupta@freescale.com>
Signed-off-by: Gaurav Rana <gaurav.rana@freescale.com>
CC: Simon Glass <sjg@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/Kconfig b/Kconfig
index 75bab7f..fb012cf 100644
--- a/Kconfig
+++ b/Kconfig
@@ -141,7 +141,9 @@
 	select RSA
 	help
 	  This option enables signature verification of FIT uImages,
-	  using a hash signed and verified using RSA.
+	  using a hash signed and verified using RSA. If
+	  CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
+	  hashing is available using hardware, RSA library will use it.
 	  See doc/uImage.FIT/signature.txt for more details.
 
 config SYS_EXTRA_OPTIONS