Add hw TRNG from SEL0 SP

Intgrates the FVP TRNG into the crypto sp to provide a hw
entropy source.  Includes tests that check SP device
region configuration loading and MMIO access within the
region.

Signed-off-by: Julian Hall <julian.hall@arm.com>
Change-Id: Ia9af8b044596e1c7d194f039fdf64c2468bb3221
diff --git a/components/config/interface/platform_config.h b/components/config/interface/platform_config.h
index d11f0eb..3f7eb94 100644
--- a/components/config/interface/platform_config.h
+++ b/components/config/interface/platform_config.h
@@ -46,6 +46,13 @@
  */
 int platform_config_device_add(const struct device_region *device_region);
 
+/**
+ * \brief Returns a count of the number of device regions
+ *
+ * \return          0 if successful
+ */
+unsigned int platform_config_device_region_count(void);
+
 
 #ifdef __cplusplus
 }