checkpatch: handle FILE pointer type

When using a "FILE *" type, checkpatch considers this an error:
  ERROR: need consistent spacing around '*' (ctx:WxV)
  #32: FILE: f.c:8:
  +static void a(FILE *const b)
                      ^

Fix this by explicitly defining "FILE" as a common type.  This is useful for
user space patches.

With this patch, we now get:
   <E> <E> <_>WS( )
   <E> <E> <_>IDENT(static)
   <E> <V> <_>WS( )
   <E> <V> <_>DECLARE(void )
   <E> <T> <_>FUNC(a)
   <E> <V> <V>PAREN('(')
   <EV> <N> <_>DECLARE(FILE *const )
   <EV> <T> <_>IDENT(b)
   <EV> <V> <_>PAREN(')') -> V
   <E> <V> <_>WS(
  )
  32 > . static void a(FILE *const b)
  32 > EEVVVVVVVTTTTTVNTTTTTTTTTTTTVVV
  32 >  ______________________________

Link: https://lkml.kernel.org/r/20220902111923.1488671-1-mic@digikod.net
Link: https://lore.kernel.org/r/20220902111923.1488671-1-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Acked-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>