Correct used SLOTHY models in backend READMEs

We are now optimizing for Neoverse N1, not Cortex-A55 anymore.

Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>

Author: mkannwischer

dev/aarch64_clean/README.md

@@ -9,7 +9,7 @@ This directory contains a native backend for little endian AArch64 systems. It i
 This backend comes in two versions: "clean" and optimized. This directory contains the "clean" backend which is handwritten and
 meant to be easy to read and modify; for example, is heavily leverages register aliases and assembly macros. The optimized version
 is automatically generated from the clean one via [SLOTHY](https://github.com/slothy-optimizer/slothy). Currently, the
-target architecture is Cortex-A55, but you can easily re-optimize the code for a different microarchitecture supported
+target architecture is Neoverse N1, but you can easily re-optimize the code for a different microarchitecture supported
 by SLOTHY, by adjusting the parameters in the [Makefile](../aarch64_opt/src/Makefile).
 
 <!--- bibliography --->

dev/aarch64_opt/README.md

@@ -7,7 +7,7 @@ This directory contains a native backend for little endian AArch64 systems. It i
 ## Variants
 
 This backend comes in two versions: "clean" and optimized. The "clean" backend is handwritten and meant to be easy to read and modify; for example, is heavily leverages register aliases and assembly macros. This directory contains the optimized version, which is automatically generated from the clean one via [SLOTHY](https://github.com/slothy-optimizer/slothy). Currently, the
-target architecture is Cortex-A55, but you can easily re-optimize the code for a different microarchitecture supported
+target architecture is Neoverse N1, but you can easily re-optimize the code for a different microarchitecture supported
 by SLOTHY, by adjusting the parameters in the [Makefile](src/Makefile).
 
 <!--- bibliography --->