Use mmw to manipulate only selected bits of the word. msb and mwb verify the
memory location and may error on PLLRDY set as a result of PLLON written.
Change-Id: I9a4c1e58f002a1e5e99be1bd34aac27ba65d111d
Reported-by: Uwe Bonnes <bon@elektron.ikp.physik.tu-darmstadt.de>
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Reviewed-on: http://openocd.zylin.com/2702
Tested-by: jenkins