Setting DSP Library variant as default variant.

ARM.CMSIS.pdsc

@@ -3068,7 +3068,7 @@ and 8-bit Java bytecodes in Jazelle state.
     </component>
 
     <!-- CMSIS-DSP component -->
-    <component Cclass="CMSIS" Cgroup="DSP" Cvariant="Library" Cversion="1.5.5" condition="CMSIS DSP">
+    <component Cclass="CMSIS" Cgroup="DSP" Cvariant="Library" Cversion="1.5.5" isDefaultVariant="true" condition="CMSIS DSP">
       <description>CMSIS-DSP Library for Cortex-M, SC000, and SC300</description>
       <files>
         <!-- CPU independent -->