On j721e, its not possible to use OSPI0 and HBMC simultaneously as they
are muxed within the Flash Subsystem hence disable HBMC by default and
keep OSPI enabled. Bootloader will fixup DT when it detects HyperFlash
mux selection instead of OSPI.
Also updated detect_enable_hyperflash to use correct GPIO when checking
hypermux selection state:
* J7200 - hypermux sel connected to WKUP_GPIO0_6
* J721E - hypermux·sel·connected·to·WKUP_GPIO0_8