Blackfin: Rename IRQ flags handling functions

Rename h/w IRQ flags handling functions to be in line with what is expected for
the irq renaming patch.  This renames local_*_hw() to hard_local_*() using the
following perl command:

	perl -pi -e 's/local_irq_(restore|enable|disable)_hw/hard_local_irq_\1/ or s/local_irq_save_hw([_a-z]*)[(]flags[)]/flags = hard_local_irq_save\1()/' `find arch/blackfin/ -name "*.[ch]"`

and then fixing up asm/irqflags.h manually.

Additionally, arch/hard_local_save_flags() and arch/hard_local_irq_save() both
return the flags rather than passing it through the argument list.

Signed-off-by: David Howells <dhowells@redhat.com>