crypto/fsl: Introduce SPL_FSL_CAAM_RNG

Add SPL variant of SPL_FSL_CAAM_RNG so that the SPL_FSL_CAAM_RNG can
be disabled in SPL if necessary. This may be necessary due to e.g.
size constraints of the SPL.

Signed-off-by: Marek Vasut <marex@denx.de>
diff --git a/drivers/crypto/fsl/Kconfig b/drivers/crypto/fsl/Kconfig
index 294e1c8..9f58731 100644
--- a/drivers/crypto/fsl/Kconfig
+++ b/drivers/crypto/fsl/Kconfig
@@ -78,6 +78,13 @@
 	  using the prediction resistance flag which means the DRGB is
 	  reseeded from the TRNG every time random data is generated.
 
+config SPL_FSL_CAAM_RNG
+	bool "Enable CAAM Random Number Generator support in SPL"
+	depends on SPL_DM_RNG
+	help
+	  This option is an SPL-variant of the FSL_CAAM_RNG option.
+	  See the help of FSL_CAAM_RNG for details.
+
 endif
 
 config FSL_DCP_RNG