arm_adi_v5: reduce some CSW writes

arm_adi_v5: reduce some CSW writes

MEM-AP access through banked data registers MEM_AP_REG_BD0..3
does not increment TAR regardless of the current autoincrement mode.
mem_ap_read_u32() and mem_ap_write_u32() can keep the current
autoincrement mode instead of switching autoincrement off.

Change-Id: Ib7ec688d3e04f1da678363cd2819ce90e8910e58
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: http://openocd.zylin.com/4163
Tested-by: jenkins
Reviewed-by: Andreas Bolsch <hyphen0break@gmail.com>
Reviewed-by: Christopher Head <chead@zaber.com>
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>