watchdog: Remove redundant of_match_ptr

of_match_ptr() is a macro used to avoid undefined reference error if
CONFIG_OF is used to selectively compile in or out the
data structure. It is defined as follows:

#ifdef CONFIG_OF
#define of_match_ptr(ptr) ptr
#else
#define of_match_ptr(ptr) NULL
#endif

In the case of this series, none of the drivers use CONFIG_OF macro to
compile out the data structure (i.e., the data structure is always
defined).
Hence the use of of_match_ptr() does not make any sense. Thus removing
it to make the code look simpler for readability.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>