Pull code from arch/*/irq.rs to trap/irq.rs

ostd/src/arch/riscv/mod.rs

@@ -25,7 +25,6 @@ pub(crate) fn init_cvm_guest() {
 pub(crate) unsafe fn late_init_on_bsp() {
     // SAFETY: This function is called in the boot context of the BSP.
     unsafe { trap::init() };
-    irq::init();
 
     // SAFETY: We're on the BSP and we're ready to boot all APs.
     unsafe { crate::boot::smp::boot_all_aps() };