MIPS: Remove irqflags.h dependency from bitops.h

MIPS: Remove irqflags.h dependency from bitops.h

The "else clause" of most functions in bitops.h invoked
raw_local_irq_{save,restore}() and in doing so had a dependency on
irqflags.h.  This fix moves said code to bitops.c, removing the
dependency.

Signed-off-by: Jim Quinlan <[email protected]>
Cc: [email protected]
Cc: David Daney <[email protected]>
Cc: Kevin Cernekee [email protected]
Cc: Jim Quinlan <[email protected]>
Patchwork: https://patchwork.linux-mips.org/patch/4320/
Signed-off-by: Ralf Baechle <[email protected]>