i2c: sprd: depend on COMMON_CLK to fix compile tests

The I2C_SPRD uses Common Clock Framework thus it cannot be built on
platforms without it (e.g. compile test on MIPS with LANTIQ):

    /usr/bin/mips-linux-gnu-ld: drivers/i2c/busses/i2c-sprd.o: in function `sprd_i2c_probe':
    i2c-sprd.c:(.text.sprd_i2c_probe+0x254): undefined reference to `clk_set_parent'

Fixes: 4a2d5f6 ("i2c: Enable compile testing for more drivers")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

drivers/i2c/busses/Kconfig

@@ -1013,6 +1013,7 @@ config I2C_SIRF
 config I2C_SPRD
 	tristate "Spreadtrum I2C interface"
 	depends on I2C=y && (ARCH_SPRD || COMPILE_TEST)
+	depends on COMMON_CLK
 	help
 	  If you say yes to this option, support will be included for the
 	  Spreadtrum I2C interface.