lib/rsa: Add Kconfig for devices supporting RSA Modular Exponentiation

Kconfig option added for devices which support RSA Verification.
1. RSA_SOFTWARE_EXP
Enables driver for supporting RSA Modular Exponentiation in Software
2. RSA_FREESCALE_EXP
Enables driver for supporting RSA Modular Exponentiation using Freescale specific
driver

The above drivers use RSA uclass

Signed-off-by: Ruchika Gupta <ruchika.gupta@freescale.com>
CC: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
(Removed duplicate line in Kconfig comment)

Change-Id: I7663c4d5350e2bfc3dfa2696f70ef777d6ccc6f6

lib/Kconfig

@@ -27,11 +27,6 @@ config SYS_HZ
 	  get_timer() must operate in milliseconds and this option must be
 	  set to 1000.
 
-config RSA
-	bool "Use RSA Library"
-	help
-	  RSA support. This enables the RSA algorithm used for FIT image
-	  verification in U-Boot.
-	  See doc/uImage.FIT/signature.txt for more details.
+source lib/rsa/Kconfig
 
 endmenu

lib/rsa/Kconfig

@@ -0,0 +1,27 @@
+config RSA
+	bool "Use RSA Library"
+	select RSA_FREESCALE_EXP if FSL_CAAM
+	select RSA_SOFTWARE_EXP if !RSA_FREESCALE_EXP
+	help
+	  RSA support. This enables the RSA algorithm used for FIT image
+	  verification in U-Boot.
+	  See doc/uImage.FIT/signature.txt for more details.
+
+if RSA
+config RSA_SOFTWARE_EXP
+	bool "Enable driver for RSA Modular Exponentiation in software"
+	depends on DM && RSA
+	help
+	  Enables driver for modular exponentiation in software. This is a RSA
+	  algorithm used in FIT image verification. It required RSA Key as
+	  input.
+	  See doc/uImage.FIT/signature.txt for more details.
+
+config RSA_FREESCALE_EXP
+	bool "Enable RSA Modular Exponentiation with FSL crypto accelerator"
+	depends on DM && RSA && FSL_CAAM
+	help
+	Enables driver for RSA modular exponentiation using Freescale cryptographic
+	accelerator - CAAM.
+
+endif