rtc: fix build error

Fix the following build errors reported by kbuild test robot by selecting
REGMAP_SPI in Kconfig file

drivers/built-in.o: In function `ds1343_probe':
rtc-ds1343.c:(.text+0x1baf8f): undefined reference to `devm_regmap_init_spi'

Signed-off-by: Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>