[AArch64] Add Cortex-A320 scheduling model (#144385)

Instead of using the Cortex-A510 scheduling model, Cortex-A320 now uses
its own scheduling model, based off of the Cortex-A320 Software
Optimization Guide:

https://developer.arm.com/documentation/110285/r0p1

---------

Co-authored-by: Nashe Mncube <Nashe.Mncube@arm.com>

llvm/lib/Target/AArch64/AArch64.td

@@ -103,6 +103,7 @@ def MTEUnsupported : AArch64Unsupported {
 let F = [HasPAuth, HasPAuthLR] in
 def PAUnsupported : AArch64Unsupported;
 
+include "AArch64SchedA320.td"
 include "AArch64SchedA53.td"
 include "AArch64SchedA55.td"
 include "AArch64SchedA510.td"

llvm/lib/Target/AArch64/AArch64Processors.td

@@ -1131,7 +1131,7 @@ def : ProcessorModel<"cortex-a34", CortexA53Model, ProcessorFeatures.A53,
                      [TuneA35]>;
 def : ProcessorModel<"cortex-a35", CortexA53Model, ProcessorFeatures.A53,
                      [TuneA35]>;
-def : ProcessorModel<"cortex-a320", CortexA510Model, ProcessorFeatures.A320,
+def : ProcessorModel<"cortex-a320", CortexA320Model, ProcessorFeatures.A320,
                      [TuneA320]>;
 def : ProcessorModel<"cortex-a53", CortexA53Model, ProcessorFeatures.A53,
                      [TuneA53]>;