Build: Semantic versioning support

This patch modifies the project's versioning
schema to support semantic versioning.

The new schema going forward is:

<Major>.<Minor>.Hotfix>

The patch updates:

• The TF-M version macros
* Previous releases' documentation
* The version detection logic for documentation to support
  old and new schema

Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
Change-Id: I6baa0cab849d656c8d756d4a70c10c258ef3001c
diff --git a/secure_fw/spm/include/tfm_version.h b/secure_fw/spm/include/tfm_version.h
index 9924146..25354e9 100644
--- a/secure_fw/spm/include/tfm_version.h
+++ b/secure_fw/spm/include/tfm_version.h
@@ -13,12 +13,13 @@
  */
 #define VERSION_MAJOR    1
 #define VERSION_MINOR    1
+#define VERSION_HOTFIX   0
 #define VERSION_STRING   ""
 
 #define VERSTR(x)      #x
-#define VERCON(major, minor) VERSTR(major)"."VERSTR(minor)
+#define VERCON(major, minor, hotfix) VERSTR(major)"."VERSTR(minor)"."VERSTR(hotfix)
 
-#define VERSION_FULLSTR VERCON(VERSION_MAJOR, VERSION_MINOR)""VERSION_STRING
+#define VERSION_FULLSTR VERCON(VERSION_MAJOR, VERSION_MINOR, VERSION_HOTFIX)""VERSION_STRING