Linux 6.6 config issues

[shenki]

@geissonator reported:

The phosphor-buttons service is core dumping with this in romulus QEMU:

Nov 29 03:24:09 romulus buttons[412]: Start Phosphor buttons service...
Nov 29 03:24:09 romulus buttons[412]: terminate called after throwing an instance of 'std::filesystem::__cxx11::filesystem_error'
Nov 29 03:24:09 romulus buttons[412]:   what():  filesystem error: directory iterator cannot open directory: No such file or directory [/sys/class/gpio]

This is because CONFIG_GPIO_SYSFS is no longer set in the config.

We used to have EMBEDDED=y, which selected EXPERT. As CONFIG_GPIO_SYSFS depends on EXPERT, we lost that setting (and a bunch of other ones).

An update to the defconfig is required.