remoteproc: ops: Add elf section size as input parameter to device_to_virt api

Introduce a new parameter "size" that accepts size of the region to
remoteproc ops callback device_to_virt(). This can enforce more checks
on the region that device_to_virt() is dealing with.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Tested-by: Fabien Dessenne <fabien.dessenne@st.com>
Reviewed-by: Fabien Dessenne <fabien.dessenne@st.com>