drivers/rtc/rtc-s3c.c: fix incorrect way of save/restore of S3C2410_TICNT for TYPE_S3C64XX

On exynos5250, exynos5420 and exynos5260 it was observed that, after 1
cycle of S2R, the rtc-tick occurs at a very fast rate as compared to the
rtc-tick occuring before S2R.

This patch fixes the above issue by correcting the wrong way of
save/restore of S3C2410_TICNT for TYPE_S3C64XX.

Signed-off-by: Vikas Sajjan <vikas.sajjan@samsung.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>