Add protection in dram_bank_mmu_setup() to avoid access to bd->bi_dram
before relocation.
This patch allow to use the generic weak function dram_bank_mmu_setup
to activate the MMU and the data cache in SPL or in U-Boot before
relocation, when bd->bi_dram is not yet initialized.
In this cases, the MMU must be initialized explicitly with
mmu_set_region_dcache_behaviour function.
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
c8ec1e3ff5