arm64: defconfig: enable I2C_DESIGNWARE_CORE with I2C_DESIGNWARE_PLATFORM

The dependency handling of the Synopsys DesignWare I2C
adapter drivers is going to be changed so that the glue
drivers for the PCI and platform buses depend on
I2C_DESIGNWARE_CORE.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>