board: ti: j721e: Add support for HyperFlash detection

On J7200 SoC OSPI0 and HypeFlash are muxed at HW level and only one of
them can be used at any time. J7200 EVM has both HyperFlash and OSPI
flash on board. There is a user switch (SW3.1) that can be toggled to
select OSPI flash vs HyperFlash.
Read the state of this switch via wkup_gpio0_6 line and fixup the DT
nodes to select OSPI0 vs HyperFlash

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>