[REFACTOR] Move vCPU code to separate file

This is to facilitate having a better framework for controlling access to CPU
features and registers.

Bug: 144898870
Change-Id: I68d7f08a4cce8e6b0bf2aa0325254a8a26fbf7fc
diff --git a/src/arch/fake/hypervisor/cpu.c b/src/arch/fake/hypervisor/cpu.c
index 71d6f92..8014b3f 100644
--- a/src/arch/fake/hypervisor/cpu.c
+++ b/src/arch/fake/hypervisor/cpu.c
@@ -16,6 +16,7 @@
 
 #include "hf/arch/cpu.h"
 
+#include "hf/cpu.h"
 #include "hf/spci.h"
 
 void arch_irq_disable(void)
@@ -28,14 +29,10 @@
 	/* TODO */
 }
 
-void arch_regs_reset(struct arch_regs *r, bool is_primary, spci_vm_id_t vm_id,
-		     cpu_id_t vcpu_id, paddr_t table)
+void arch_regs_reset(struct vcpu *vcpu)
 {
 	/* TODO */
-	(void)is_primary;
-	(void)vm_id;
-	(void)table;
-	r->vcpu_id = vcpu_id;
+	(void)vcpu;
 }
 
 void arch_regs_set_pc_arg(struct arch_regs *r, ipaddr_t pc, uintreg_t arg)