qat: Fix firmware module autoloading

qat: Fix firmware module autoloading

If firmware_get() fails to find a loaded firmware image, it searches for
candidate KLDs to load.  It will search for a KLD containing a module
with the same name as the requested image, and failing that, will load a
KLD with the same basename as the requested image.

The module name given by fw_stub.awk is simply "<mangled KLD name>_fw".

QAT firmware modules contain two images, neither of which match either
of the names used during lookup, so automatic loading of firmware images
after mountroot does not work.  Work around this by using the same
string for the first image name and for the KLD basename.

MFC after:	3 days
Sponsored by:	Rubicon Communications, LLC (Netgate)