libfcoe: Add runtime debugging with module param debug_logging

This patch adds a 'debug_logging' module parameter to
libfcoe.ko. It is an unsigned int that represents a bitmask of
available debug logging levels, each of which can be tuned at
runtime. Currently there are only two logging levels for this
module-

   bit
LSB 0 = libfcoe general logging
    1 = FIP logging

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>