ptp: make ptp_clock_info const

Make these const as they are only used in a copy operation.
Done using Coccinelle.

@match disable optional_qualifier@
identifier s;
@@
static struct ptp_clock_info s = {...};

@ref@
position p;
identifier match.s;
@@
s@p

@good1@
position ref.p;
identifier match.s,f,c;
expression e;
@@
(
e = s@p
|
e = s@p.f
|
c(...,s@p.f,...)
|
c(...,s@p,...)
)

@bad depends on  !good1@
position ref.p;
identifier match.s;
@@
s@p

@depends on forall !bad disable optional_qualifier@
identifier match.s;
@@
static
+ const
struct ptp_clock_info s;

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>