lib/rsa: Kconfig: Remove superfluous 'depends on RSA'

RSA_SOFTWARE_EXP and RSA_FREESCALE_EXP are wrapped inside:

if RSA
	...
endif

So, remove the redundant "depends on RSA" from their depends expression.
In addition, move SPL_RSA into the same "if RSA ... endif" block, since
its only direct dependeny is CONFIG_RSA. This tidies up and simplifies
reading of lib/rsa/Kconfig.

No functional change intended.

Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/rsa/Kconfig b/lib/rsa/Kconfig
index fde1ac1..2b33f32 100644
--- a/lib/rsa/Kconfig
+++ b/lib/rsa/Kconfig
@@ -13,14 +13,14 @@
 	  option. The software based modular exponentiation is built into
 	  mkimage irrespective of this option.
 
+if RSA
+
 config SPL_RSA
 	bool "Use RSA Library within SPL"
-	depends on RSA
 
-if RSA
 config RSA_SOFTWARE_EXP
 	bool "Enable driver for RSA Modular Exponentiation in software"
-	depends on DM && RSA
+	depends on DM
 	help
 	  Enables driver for modular exponentiation in software. This is a RSA
 	  algorithm used in FIT image verification. It required RSA Key as
@@ -29,7 +29,7 @@
 
 config RSA_FREESCALE_EXP
 	bool "Enable RSA Modular Exponentiation with FSL crypto accelerator"
-	depends on DM && RSA && FSL_CAAM && !ARCH_MX7 && !ARCH_MX6 && !ARCH_MX5
+	depends on DM && FSL_CAAM && !ARCH_MX7 && !ARCH_MX6 && !ARCH_MX5
 	help
 	Enables driver for RSA modular exponentiation using Freescale cryptographic
 	accelerator - CAAM.