SPRT: Rename the folder name to 'runtime'

The original name 'sprt' can be confusing if user did not read
SPRTL related document, hence rename it as 'runtime' to
indicate it is a secure partition runtime API set.

Signed-off-by: Ken Liu <Ken.Liu@arm.com>
Change-Id: I3ba7d5e80dd2ee32d52463bcdf012a2f5bf6017c
diff --git a/docs/technical_references/design_docs/source_structure.rst b/docs/technical_references/design_docs/source_structure.rst
index 74219d0..a42529e 100644
--- a/docs/technical_references/design_docs/source_structure.rst
+++ b/docs/technical_references/design_docs/source_structure.rst
@@ -117,8 +117,8 @@
 ================================= =============================================
 Folder name                       Purpose
 ================================= =============================================
-lib/sprt/\*                       The SPRTL sources and intermedia files. [1]
-lib/sprt/shared\*                 Sources can be shared by out of SPRTL. [2]
+lib/runtime/\*                    The SPRTL sources and intermedia files. [1]
+lib/runtime/shared\*              Sources can be shared by out of SPRTL. [2]
 <partition_x>/\*                  Files for 'partition_x'.
 <partition_x>/include/\*          RoT Service API headers of 'partition_x'. [3]
 <partition_y>/\*                  Files for 'partition_y'.
diff --git a/docs/technical_references/design_docs/tfm_secure_partition_runtime_library.rst b/docs/technical_references/design_docs/tfm_secure_partition_runtime_library.rst
index 97e8444..6df1c28 100644
--- a/docs/technical_references/design_docs/tfm_secure_partition_runtime_library.rst
+++ b/docs/technical_references/design_docs/tfm_secure_partition_runtime_library.rst
@@ -308,7 +308,7 @@
 Implementation
 ==============
 The SPRTL C Runtime sources are put under:
-'$TFM_ROOT/secure_fw/partitions/lib/sprt/'
+'$TFM_ROOT/secure_fw/partitions/lib/runtime/'
 
 The output of this folder is a static library named as 'libtfm_sprt.a'. The code
 of 'libtfm_sprt.a' is put into a dedicated section so that a hardware protected