nodedev: Move the sysfs-related cap handling to node_device_conf.c

nodedev: Move the sysfs-related cap handling to node_device_conf.c

The capabilities are defined/parsed/formatted/queried from this module,
no reason for 'update' not being part of the module as well. This also
involves some module-specific prefix changes.
This patch also drops the node_device_linux_sysfs module from the repo
since:
a) it only contained the capability handlers we just moved
b) it's only linked with the driver (by design) and thus unreachable to
other modules
c) we touch sysfs across all the src/util modules so the module being
deleted hasn't been serving its original intention for some time already.

Signed-off-by: Erik Skultety <eskultet@redhat.com>