Staging: silicom: move symbol exports beneath definitions in bpctl_mod.c

Move the EXPORT_SYMBOL macros in bpctl_mod.c beneath the definitions
they refer to, resolving checkpatch.pl warnings. While we're at it, use
EXPORT_SYMBOL rather than EXPORT_SYMBOL_NOVERS.

Signed-off-by: Chad Williamson <chad@dahc.us>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>