GPU: Increase default number of threads on AMD Vega GPU family

Author: Jorge Parada

GPU/Common/GPUDefGPUParameters.h

@@ -23,10 +23,10 @@
 #if defined(GPUCA_GPUTYPE_VEGA)
   #define GPUCA_BLOCK_COUNT_CONSTRUCTOR_MULTIPLIER 2
   #define GPUCA_BLOCK_COUNT_SELECTOR_MULTIPLIER 4
-  #define GPUCA_THREAD_COUNT 128
-  #define GPUCA_THREAD_COUNT_CONSTRUCTOR 128
-  #define GPUCA_THREAD_COUNT_SELECTOR 128
-  #define GPUCA_THREAD_COUNT_FINDER 128
+  #define GPUCA_THREAD_COUNT 256
+  #define GPUCA_THREAD_COUNT_CONSTRUCTOR 256
+  #define GPUCA_THREAD_COUNT_SELECTOR 256
+  #define GPUCA_THREAD_COUNT_FINDER 256
   #define GPUCA_NEIGHBOURS_FINDER_MAX_NNEIGHUP 0
   #define GPUCA_TRACKLET_SELECTOR_HITS_REG_SIZE 12
 #elif defined(GPUCA_GPUTYPE_TURING)