core/arm: Drop ChangeProcessorID.

This code was used to switch the CPU ID on thread switches.
However since "hle: kernel: multicore: Replace n-JITs impl. with 4 JITs.", the CPU ID is not a constant.
This has been dead code since this rewrite, and dropped in dynarmic as well. So there is no need to keep it.

src/core/arm/arm_interface.h

@@ -159,8 +159,6 @@ public:
      */
     virtual void SetTPIDR_EL0(u64 value) = 0;
 
-    virtual void ChangeProcessorID(std::size_t new_core_id) = 0;
-
     virtual void SaveContext(ThreadContext32& ctx) = 0;
     virtual void SaveContext(ThreadContext64& ctx) = 0;
     virtual void LoadContext(const ThreadContext32& ctx) = 0;

src/core/arm/dynarmic/arm_dynarmic_32.cpp

@@ -255,10 +255,6 @@ void ARM_Dynarmic_32::SetTPIDR_EL0(u64 value) {
     cp15->uprw = static_cast<u32>(value);
 }
 
-void ARM_Dynarmic_32::ChangeProcessorID(std::size_t new_core_id) {
-    jit->ChangeProcessorID(new_core_id);
-}
-
 void ARM_Dynarmic_32::SaveContext(ThreadContext32& ctx) {
     Dynarmic::A32::Context context;
     jit->SaveContext(context);

src/core/arm/dynarmic/arm_dynarmic_32.h

@@ -48,7 +48,6 @@ public:
     void SetTlsAddress(VAddr address) override;
     void SetTPIDR_EL0(u64 value) override;
     u64 GetTPIDR_EL0() const override;
-    void ChangeProcessorID(std::size_t new_core_id) override;
 
     bool IsInThumbMode() const {
         return (GetPSTATE() & 0x20) != 0;

src/core/arm/dynarmic/arm_dynarmic_64.cpp

@@ -296,10 +296,6 @@ void ARM_Dynarmic_64::SetTPIDR_EL0(u64 value) {
     cb->tpidr_el0 = value;
 }
 
-void ARM_Dynarmic_64::ChangeProcessorID(std::size_t new_core_id) {
-    jit->ChangeProcessorID(new_core_id);
-}
-
 void ARM_Dynarmic_64::SaveContext(ThreadContext64& ctx) {
     ctx.cpu_registers = jit->GetRegisters();
     ctx.sp = jit->GetSP();

src/core/arm/dynarmic/arm_dynarmic_64.h

@@ -45,7 +45,6 @@ public:
     void SetTlsAddress(VAddr address) override;
     void SetTPIDR_EL0(u64 value) override;
     u64 GetTPIDR_EL0() const override;
-    void ChangeProcessorID(std::size_t new_core_id) override;
 
     void SaveContext(ThreadContext32& ctx) override {}
     void SaveContext(ThreadContext64& ctx) override;