samples: Add manufacturing date to pass BINFO_2_1

There was a missing Kconfig for manufacturing date. To pass the
test we cannot use the default value.

Signed-off-by: Arkadiusz Balys <arkadiusz.balys@nordicsemi.no>

Author: ArekBalysNordic

subsys/certification/thread_platform/overlay-thread_platform.conf

@@ -23,6 +23,7 @@ CONFIG_CHIP_DEVICE_DISCRIMINATOR=3000
 CONFIG_CHIP_DEVICE_SPAKE2_PASSCODE=30303030
 CONFIG_CHIP_DEVICE_VENDOR_ID=4735
 CONFIG_CHIP_DEVICE_PRODUCT_ID=784
+CONFIG_CHIP_DEVICE_MANUFACTURING_DATE="2026-08-19"
 CONFIG_CHIP_DEVICE_VENDOR_NAME="Nordic Semiconductor"
 CONFIG_CHIP_DEVICE_PRODUCT_NAME="nRFConnect SDK Platform"
 CONFIG_CHIP_MALLOC_SYS_HEAP_WATERMARKS_SUPPORT=y