drivers/rtc/rtc-s3c.c: fix initialization failure without rtc source clock
drivers/rtc/rtc-s3c.c: fix initialization failure without rtc source clock

Fix unconditional initialization failure on non-exynos3250 SoCs.

Commit df9e26d093d3 ("rtc: s3c: add support for RTC of Exynos3250 SoC")
introduced rtc source clock support, but also added initialization
failure on SoCs, which doesn't need such clock.

Signed-off-by: Marek Szyprowski <2a0259761cc3e88db42be5300c1579a67c77e65e@samsung.com>
Reviewed-by: Chanwoo Choi <42eed19c0f56a8d487deac90c6d19d6364b7ba73@samsung.com>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs