fix(st): support device tree DDR sizes higher than 16Gbits for aarch64

In that case, memory address space is higher than 4GB, so 32-bits
addressing is not enough.
Get st,mem-size property value on 64bits (size_t type in structures).

Signed-off-by: Nicolas Le Bayon <nicolas.le.bayon@st.com>
Signed-off-by: Maxime Méré <maxime.mere@foss.st.com>
Change-Id: I1df23bfa7a850fc3f5a4ef9fc5d2f76ab6c6dea8
1 file changed