hw/arm/virt: Fix incorrect non-secure flash dtb node name

hw/arm/virt: Fix incorrect non-secure flash dtb node name

In the virt board with secure=on we put two nodes in the dtb
for flash devices: one for the secure-only flash, and one
for the non-secure flash. We get the reg properties for these
correct, but in the DT node name, which by convention includes
the base address of devices, we used the wrong address. Fix it.

Spotted by dtc, which will complain
Warning (unique_unit_address): /flash@0: duplicate unit-address (also used in node /secflash@0)
if you dump the dtb from QEMU with -machine dumpdtb=file.dtb
and then decompile it with dtc.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220513131316.4081539-2-peter.maydell@linaro.org