ARM: multi_v7_defconfig: Enable Exynos platform

Enable Exynos platform and its related IPs for multi_v7_defconfig.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Olof Johansson <olof@lixom.net>