Add sp environment documentation

Explain differences between opteesp and sp environments, along
documenting the build process of sp deployments.

Signed-off-by: Imre Kis <imre.kis@arm.com>
Change-Id: I036c30e730c355c134d3167f44723cd3a400bf77
diff --git a/docs/deployments/secure-partitions.rst b/docs/deployments/secure-partitions.rst
index 338363c..7727de9 100644
--- a/docs/deployments/secure-partitions.rst
+++ b/docs/deployments/secure-partitions.rst
@@ -23,6 +23,7 @@
 
   * - Supported Environments
     - * *opteesp* (runs as an S-EL0 SP under OP-TEE)
+      * *sp* (SPMC agnostic S-EL0 SP format)
   * - External Dependencies
     - * | TRNG (platform specific)
       * | Secure storage SP
@@ -42,6 +43,7 @@
 
   * - Supported Environments
     - * *opteesp* (runs as an S-EL0 SP under OP-TEE)
+      * *sp* (SPMC agnostic S-EL0 SP format)
   * - External Dependencies
     - * | TPM Event Log (via SP boot parameter)
       * | Crypto SP
@@ -62,6 +64,7 @@
 
   * - Supported Environments
     - * *opteesp* (runs as an S-EL0 SP under OP-TEE)
+      * *sp* (SPMC agnostic S-EL0 SP format)
   * - External Dependencies
     - * Depends on configured storage backend
 
@@ -88,6 +91,7 @@
 
   * - Supported Environments
     - * *opteesp* (runs as an S-EL0 SP under OP-TEE)
+      * *sp* (SPMC agnostic S-EL0 SP format)
   * - External Dependencies
     - * SE communication peripheral (platform specific)
 
@@ -104,6 +108,7 @@
 
   * - Supported Environments
     - * *opteesp* (runs as an S-EL0 SP under OP-TEE)
+      * *sp* (SPMC agnostic S-EL0 SP format)
   * - External Dependencies
     - * | Secure storage service instance (e.g. hosted by protected-storage SP)
       * | Crypto service instance (e.g. hosted crypto SP)
@@ -123,11 +128,12 @@
 
   * - Supported Environments
     - * *opteesp* (runs as an S-EL0 SP under OP-TEE)
+      * *sp* (SPMC agnostic S-EL0 SP format)
   * - External Dependencies
     - * Any hardware accessed by test cases (platform specific)
 
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-*Copyright (c) 2022, Arm Limited and Contributors. All rights reserved.*
+*Copyright (c) 2022-2023, Arm Limited and Contributors. All rights reserved.*
 
 SPDX-License-Identifier: BSD-3-Clause