hexagon: vm_fault: include asm/vm_fault.h for prototypes

Clang warns:

  arch/hexagon/mm/vm_fault.c:157:6: warning: no previous prototype for function 'read_protection_fault' [-Wmissing-prototypes]
    157 | void read_protection_fault(struct pt_regs *regs)
        |      ^
  arch/hexagon/mm/vm_fault.c:157:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
    157 | void read_protection_fault(struct pt_regs *regs)
        | ^
        | static
  arch/hexagon/mm/vm_fault.c:164:6: warning: no previous prototype for function 'write_protection_fault' [-Wmissing-prototypes]
    164 | void write_protection_fault(struct pt_regs *regs)
        |      ^
  arch/hexagon/mm/vm_fault.c:164:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
    164 | void write_protection_fault(struct pt_regs *regs)
        | ^
        | static
  arch/hexagon/mm/vm_fault.c:171:6: warning: no previous prototype for function 'execute_protection_fault' [-Wmissing-prototypes]
    171 | void execute_protection_fault(struct pt_regs *regs)
        |      ^
  arch/hexagon/mm/vm_fault.c:171:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
    171 | void execute_protection_fault(struct pt_regs *regs)
        | ^
        | static

The prototypes for these functions are defined in asm/vm_fault.h, so
include it to pick them up and silence the warnings.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Nathan Chancellor <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Brian Cain <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

arch/hexagon/mm/vm_fault.c

@@ -12,6 +12,7 @@
  */
 
 #include <asm/traps.h>
+#include <asm/vm_fault.h>
 #include <linux/uaccess.h>
 #include <linux/mm.h>
 #include <linux/sched/signal.h>