[HALX86] Rearrange files in x86 HAL

- Rename UP -> PIC. The "up" folder in fact contains the code for
  managing the Intel 8259 PIC chip
- Move amd64/processor.c -> apic/processor.c. The code is not tied to
  amd64
- Remove platform from "halinit*" files. They already reside in the
  corresponding folder

hal/halx86/apic/processor.c

@@ -0,0 +1,76 @@
+/*
+ * PROJECT:     ReactOS Hardware Abstraction Layer
+ * LICENSE:     GPL-2.0-or-later (https://spdx.org/licenses/GPL-2.0-or-later)
+ * PURPOSE:     HAL Processor Routines
+ * COPYRIGHT:   Copyright 2010 Timo Kreuzer <timo.kreuzer@reactos.org>
+ */
+
+/* INCLUDES ******************************************************************/
+
+#include <hal.h>
+#define NDEBUG
+#include <debug.h>
+
+KAFFINITY HalpActiveProcessors;
+KAFFINITY HalpDefaultInterruptAffinity;
+
+/* PRIVATE FUNCTIONS *********************************************************/
+
+VOID
+NTAPI
+HaliHaltSystem(VOID)
+{
+    /* Disable interrupts and halt the CPU */
+    _disable();
+    __halt();
+}
+
+/* FUNCTIONS *****************************************************************/
+
+/*
+ * @implemented
+ */
+BOOLEAN
+NTAPI
+HalAllProcessorsStarted(VOID)
+{
+    /* Do nothing */
+    return TRUE;
+}
+
+/*
+ * @implemented
+ */
+BOOLEAN
+NTAPI
+HalStartNextProcessor(IN PLOADER_PARAMETER_BLOCK LoaderBlock,
+                      IN PKPROCESSOR_STATE ProcessorState)
+{
+    /* Ready to start */
+    return FALSE;
+}
+
+/*
+ * @implemented
+ */
+VOID
+NTAPI
+HalProcessorIdle(VOID)
+{
+    /* Enable interrupts and halt the processor */
+    _enable();
+    __halt();
+}
+
+/*
+ * @implemented
+ */
+VOID
+NTAPI
+HalRequestIpi(KAFFINITY TargetProcessors)
+{
+    UNIMPLEMENTED;
+    __debugbreak();
+}
+
+/* EOF */