arm64: irq: include <linux/cpumask.h>

Sorting include files in alphabetic order in
drivers/tty/serial/samsung.c revealed the following error:

In file included from drivers/tty/serial/samsung_tty.c:24:
./arch/arm64/include/asm/irq.h:9:43: error: unknown type name ‘cpumask_t’
    9 | void arch_trigger_cpumask_backtrace(const cpumask_t *mask, int exclude_cpu);
      |                                           ^~~~~~~~~

Include cpumask.h to avoid unknown type errors for parents of irq.h that
don't include cpumask.h.

Acked-by: Mark Rutland <[email protected]>
Signed-off-by: Tudor Ambarus <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>

Author: ambarus

arch/arm64/include/asm/irq.h

@@ -4,6 +4,8 @@
 
 #ifndef __ASSEMBLER__
 
+#include <linux/cpumask.h>
+
 #include <asm-generic/irq.h>
 
 void arch_trigger_cpumask_backtrace(const cpumask_t *mask, int exclude_cpu);