PSoC: Align 8 bytes functions configuration in ARMClang

PSoC64 functions are permitted to depend on the 8-byte aligment of
8-byte data items, while the NS startup file doesn't require code
to preserve 8-byte data objects. That makes a warning when building.

Signed-off-by: Jianliang Shen <jianliang.shen@arm.com>
Change-Id: If149282cbaca94e75e367116308a6e0fe933b18f
diff --git a/platform/ext/target/cypress/psoc64/Device/Source/armclang/startup_psoc64_ns.s b/platform/ext/target/cypress/psoc64/Device/Source/armclang/startup_psoc64_ns.s
index 6fb6f2c..4e67469 100644
--- a/platform/ext/target/cypress/psoc64/Device/Source/armclang/startup_psoc64_ns.s
+++ b/platform/ext/target/cypress/psoc64/Device/Source/armclang/startup_psoc64_ns.s
@@ -24,6 +24,8 @@
 ;//-------- <<< Use Configuration Wizard in Context Menu >>> ------------------
 ;*/
 
+                PRESERVE8
+
                 IMPORT |Image$$ARM_LIB_STACK$$ZI$$Limit|
 
 ; The CPU VTOR register