SWITCH_RATIO for Arm(R) Neoverse(TM) architecture

This seems like a good balance of values for reasonably sized matrices. With `SWITCH_RATIO=16` the DGEMM scales better to bigger sizes but the better solution would be some kind of
thread throttling so I've gone with `SWITCH_RATIO=8`.

Author: Mousius

param.h

@@ -1,5 +1,6 @@
 /*****************************************************************************
 Copyright (c) 2011-2014, The OpenBLAS Project
+Copyright (c) 2022, Arm Ltd
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -3338,6 +3339,12 @@ is a big desktop or server with abundant cache rather than a phone or embedded d
 
 #elif defined(NEOVERSEN1)
 
+#if defined(XDOUBLE) || defined(DOUBLE)
+#define SWITCH_RATIO            8
+#else
+#define SWITCH_RATIO            16
+#endif
+
 #define SGEMM_DEFAULT_UNROLL_M  16
 #define SGEMM_DEFAULT_UNROLL_N  4
 
@@ -3367,7 +3374,11 @@ is a big desktop or server with abundant cache rather than a phone or embedded d
 
 #elif defined(NEOVERSEV1)
 
-#define SWITCH_RATIO  16
+#if defined(XDOUBLE) || defined(DOUBLE)
+#define SWITCH_RATIO            8
+#else
+#define SWITCH_RATIO            16
+#endif
 
 #define SGEMM_DEFAULT_UNROLL_M  16
 #define SGEMM_DEFAULT_UNROLL_N  4
@@ -3398,6 +3409,12 @@ is a big desktop or server with abundant cache rather than a phone or embedded d
 
 #elif defined(NEOVERSEN2)
 
+#if defined(XDOUBLE) || defined(DOUBLE)
+#define SWITCH_RATIO            8
+#else
+#define SWITCH_RATIO            16
+#endif
+
 #undef SBGEMM_ALIGN_K
 #define SBGEMM_ALIGN_K 4