misc: pci_endpoint_test: Add deviceID for J721S2 PCIe EP device support

Add DEVICE_ID for J721S2 and enable support for endpoints configured
with this DEVICE_ID in the pci_endpoint_test driver.

Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Cc: stable <stable@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20231020120248.3168406-1-s-vadapalli@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>