SPI Slave mode SS pin not connected right

[RupertAmann]

vivado-boards/new/board_files/arty-a7-35/E.0/board.xml

Line 542 in 18d7d68

<pin_map port_index="0" component_pin="spi_ss_i"/>

ss_i component pin "is not used in any mode": https://www.xilinx.com/support/documentation/ip_documentation/axi_quad_spi/v3_2/pg153-axi-quad-spi.pdf, page 19

this needs to be connected to the spisel pin (page 21 in datasheet).