arm_adi_v5: deconflict local variables from global symbols

arm_adi_v5: deconflict local variables from global symbols

BeagleBone debian 7 builds produce:
   adi_v5_jtag.c: In function 'jtag_ap_q_bankselect':
   adi_v5_jtag.c:336:11: error: declaration of 'select' shadows a global declaration [-Werror=shadow]

Fix this by changing the local variable to 'sel'.

Change-Id: I8e29662ac12bc77d38d5064046d59b7364853cd9
Signed-off-by: Peter A. Bigot <pab@pabigot.com>
Reviewed-on: http://openocd.zylin.com/3184
Tested-by: jenkins
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>