arch/x86: disable i8259 in crt0.S

drivers/interrupt_controller/i8259.c is not a driver; it exists
solely to disable the i8259s when the configuration calls for it.
The six-byte sequence to mask the controllers is moved to crt0.S
and the pseudo-driver is removed.

Signed-off-by: Charles E. Youse <charles.youse@intel.com>

arch/x86/core/crt0.S

@@ -415,6 +415,17 @@ __csSet:
 1:
 #endif
 
+#if defined(CONFIG_PIC_DISABLE)
+	/*
+	 * "Disable" legacy i8259 interrupt controllers. Note that we
+	 * can't actually disable them, but we mask all their interrupt
+	 * sources which is effectively the same thing (almost).
+	 */
+	movb $0xff, %al		/* all bits set = mask all interrupts */
+	outb %al, $0x21		/* set i8259 master mask (IRQs 0-7) */
+	outb %al, $0xA1		/* set i8259 slave mask (IRQs 8-15) */
+#endif
+
 	/* Jump to C portion of kernel initialization and never return */
 
 	jmp	z_cstart

drivers/interrupt_controller/CMakeLists.txt

@@ -5,7 +5,6 @@ zephyr_sources_ifdef(CONFIG_IOAPIC                  ioapic_intr.c)
 zephyr_sources_ifdef(CONFIG_LOAPIC                  loapic_intr.c system_apic.c)
 zephyr_sources_ifdef(CONFIG_LOAPIC_SPURIOUS_VECTOR  loapic_spurious.S)
 zephyr_sources_ifdef(CONFIG_MVIC                    mvic.c)
-zephyr_sources_ifdef(CONFIG_PIC_DISABLE             i8259.c)
 zephyr_sources_ifdef(CONFIG_PLIC                    plic.c)
 zephyr_sources_ifdef(CONFIG_SHARED_IRQ              shared_irq.c)
 zephyr_sources_ifdef(CONFIG_EXTI_STM32              exti_stm32.c)