bluenrg-x: simplyfied the driver

Adopted only fast algorithm for flash programming:
- write_word and write_byte methods have been removed.
- start and end write alignments have been defined.
Moved flash controller registers offsets in a common file
shared with the flash algorithm.
- the flash base address is passed to the flash algorithm
  as a parameter.
Removed unused functions

Change-Id: I80aeab3994e477044bbcf02e66d9525dae0cb491
Signed-off-by: luca vinci <luca.vinci@st.com>
Reviewed-on: http://openocd.zylin.com/5393
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-by: Michele Sardo <msmttchr@gmail.com>

tcl/target/bluenrg-x.cfg

@@ -23,13 +23,7 @@ if { [info exists WORKAREASIZE] } {
 
 adapter speed 4000
 
-if { [info exists CPUTAPID] } {
-   set _CPUTAPID $CPUTAPID
-} else {
-   set _CPUTAPID 0x0bb11477
-}
-
-swj_newdap $_CHIPNAME cpu -expected-id $_CPUTAPID
+swj_newdap $_CHIPNAME cpu -expected-id 0x0bb11477 -expected-id 0x0bc11477
 dap create $_CHIPNAME.dap -chain-position $_CHIPNAME.cpu
 
 set _TARGETNAME $_CHIPNAME.cpu