fdtdec: optionally add property no-map to created reserved memory node

fdtdec: optionally add property no-map to created reserved memory node

Add boolean input argument @no_map to helper function
fdtdec_add_reserved_memory() to add or not "no-map" property
for an added reserved memory node.

Property no-map is used by the Linux kernel to not not map memory
in its static memory mapping. It is needed for example for the|
consistency of system non-cached memory and to prevent speculative
accesses to some firewalled memory.

No functional change. A later change will update to OPTEE library to
add no-map property to OP-TEE reserved memory nodes.

Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>