arm64: zynqmp: Do not duplicate flash partition label property

arm64: zynqmp: Do not duplicate flash partition label property

In kernel 5.4, support has been added for reading MTD devices via
the nvmem API.
For this the mtd devices are registered as read-only NVMEM providers
under sysfs with the same name as the flash partition label property.

So if flash partition label property of multiple flash devices are identical
then the second mtd device fails to get registered as a NVMEM provider.

This patch fixes the issue by having different label property for different
flashes.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>