Enable PMIC for AM437x platforms such as AM437x-sk similar to commit
a186cf10 ("ARM: omap2plus_defconfig: enable TPS65218 configs").
This allows multi_v7_defconfig to boot up on AM437x-sk platform.
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Olof Johansson <olof@lixom.net>