The eSPI, I2C, and SPI emulators use devicetree macros to build an array
of devices on the virtual bus. Currently, they will add device nodes that
are not status-okay. This leads to linker errors because the respective
device drivers would not have instantiated device structs for these
nodes --assuming the driver was even compiled. This can be frustrating
if nodes need to be disabled for debugging or configuration purposes.
Update the bus emulators to only consider status-okay nodes by changing
the macros used to iterate over bus devices.
Signed-off-by: Tristan Honscheid <honscheid@google.com>