chore(smccc): bump up SMCCC version to 1.4

TF-A code supports SMCCC spec version 1.4 while version is still kept
1.2. Bump up the version.

Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: Ie5476c4601bd504d3f3e8433e1d672ebd0a758b1
diff --git a/include/lib/smccc.h b/include/lib/smccc.h
index 63637d5..fb2b3a2 100644
--- a/include/lib/smccc.h
+++ b/include/lib/smccc.h
@@ -20,7 +20,7 @@
 						SMCCC_VERSION_MINOR_SHIFT))
 
 #define SMCCC_MAJOR_VERSION U(1)
-#define SMCCC_MINOR_VERSION U(2)
+#define SMCCC_MINOR_VERSION U(4)
 
 /*******************************************************************************
  * Bit definitions inside the function id as per the SMC calling convention