Previously when the user gets a FPGA manager, it was locked
and nobody else could use it for programming.
This commit makes it straightforward to save a reference to an
FPGA manager and only lock it when programming the FPGA.
Add functions that get an FPGA manager's mutex for exclusive use:
The following functions no longer lock an FPGA manager's mutex:
Signed-off-by: Alan Tull <email@example.com>
Acked-by: Moritz Fischer <firstname.lastname@example.org>
Signed-off-by: Greg Kroah-Hartman <email@example.com>