pipe-loader: add a dummy 'static' pipe-loader

pipe-loader: add a dummy 'static' pipe-loader

It is to be used in contrast of the dynamic one. The state-tracker does
not need to know if the pipe-driver is built into the final blob or
a separate object. This will allow us to move the logic to the final
step (in target) where the appropriate pipe-loader will be chosen.

Cc: Tom Stellard <thomas.stellard@amd.com>
Cc: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Acked-by: Rob Clark <robclark@freedesktop.org>