arch: riscv: irq_manage: add missing PLIC header

Module uses RISC-V PLIC interrupt controller API without including the
necessary headers.

Signed-off-by: Gerard Marull-Paretas <[email protected]>

Author: gmarull

arch/riscv/core/irq_manage.c

@@ -10,6 +10,10 @@
 #include <zephyr/arch/riscv/csr.h>
 #include <zephyr/irq_multilevel.h>
 
+#ifdef CONFIG_RISCV_HAS_PLIC
+#include <zephyr/drivers/interrupt_controller/riscv_plic.h>
+#endif
+
 LOG_MODULE_DECLARE(os, CONFIG_KERNEL_LOG_LEVEL);
 
 FUNC_NORETURN void z_irq_spurious(const void *unused)