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
diff --git a/drivers/crypto/fsl/Makefile b/drivers/crypto/fsl/Makefile
index 7a2543e..4fbce51 100644
--- a/drivers/crypto/fsl/Makefile
+++ b/drivers/crypto/fsl/Makefile
@@ -6,6 +6,6 @@
 obj-$(CONFIG_FSL_CAAM) += jr.o fsl_hash.o jobdesc.o error.o
 obj-$(CONFIG_CMD_BLOB)$(CONFIG_IMX_CAAM_DEK_ENCAP) += fsl_blob.o
 obj-$(CONFIG_RSA_FREESCALE_EXP) += fsl_rsa.o
-obj-$(CONFIG_FSL_CAAM_RNG) += rng.o
+obj-$(CONFIG_$(SPL_TPL_)FSL_CAAM_RNG) += rng.o
 obj-$(CONFIG_FSL_DCP_RNG) += dcp_rng.o
 obj-$(CONFIG_FSL_MFGPROT) += fsl_mfgprot.o