device.mk: move CITADEL_LAZY_PSK_SYNC definition to proprietary folder

To keep AOSP codebase clean, move CITADEL_LAZY_PSK_SYNC definition
to vendor/google_devices/<project>/proprietary/device-vendor.mk

Bug: 140835286
Change-Id: I00215c3f38d991f43ba9833dde227b59a64aa1bb
1 file changed