mtd: rawnand: qcom: Add support for secure regions in NAND memory

On a typical end product, a vendor may choose to secure some regions in
the NAND memory which are supposed to stay intact between FW upgrades.
The access to those regions will be blocked by a secure element like
Trustzone. So the normal world software like Linux kernel should not
touch these regions (including reading).

The regions are declared using a NAND chip DT property,
"secure-regions". So let's make use of this property and skip
access to the secure regions present in a system.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>