[ARM] pxa/z2: fix missing include in battery driver
Remove redundant includes and add slab.h to fix problem with building.
Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
authored by Marek Vasut and committed by Eric Miao 56b925fc 390daa0d