drivers/rtc/rtc-ds1742.c: remove redundant of_match_ptr() helper

'ds1742_rtc_of_match' is always compiled in.  Hence the helper macro is
not needed.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>