ARM: bcm: Fix bcm and multi_v7 defconfigs

BCM (Kona/capri platform) has regressed in two ways on this release. First,
bcm_defconfig no longer selected the appropriate MMC driver options due to
changes in dependencies. Secondly, the new MFD and regulator drivers were not
enabled on multi_v7_defconfig, so that caused the system to fail probing MMC
there.

Fix by enabling the new options as needed.

Cc: Matt Porter <matt.porter@linaro.org>
Cc: Christian Daudt <bcm@fixthebug.org>
Signed-off-by: Olof Johansson <olof@lixom.net>