Blackfin: move bf537-specific irq code out of common code

The SIC interrupt line muxing that the bf537 does is specific to this
CPU (thankfully), so rip it out of the common code and move it to a
bf537-specific file.  This tidies up the common code significantly.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
4 files changed