Platform: Change the HAL prototype to report status

Change the return type of tfm_spm_hal_configure_default_isolation() from
"void" to "enum tfm_plat_err_t" to report errors to caller.

Change-Id: Iadfd82e546a5141f0db1624358f09111fd7530c1
Signed-off-by: Edison Ai <edison.ai@arm.com>
diff --git a/platform/include/tfm_spm_hal.h b/platform/include/tfm_spm_hal.h
index b12df11..0435212 100644
--- a/platform/include/tfm_spm_hal.h
+++ b/platform/include/tfm_spm_hal.h
@@ -126,9 +126,11 @@
  * \param[in] partition_idx    The index of the partition that this peripheral
  *                             is assigned to.
  * \param[in] platform_data    The platform fields of the partition DB record to
- *                             be used for configuration. Can be NULL.
+ *                             be used for configuration.
+ *
+ * \return Returns values as specified by the \ref tfm_plat_err_t
  */
-void tfm_spm_hal_configure_default_isolation(
+enum tfm_plat_err_t tfm_spm_hal_configure_default_isolation(
                  uint32_t partition_idx,
                  const struct tfm_spm_partition_platform_data_t *platform_data);
 /**