target/arm_adi_v5: allow commands apsel and apcsw during init phase

target/arm_adi_v5: allow commands apsel and apcsw during init phase

The current implementation of apsel cannot be executed during the
initialization phase because it queries the DAP AP to retrieve and
print the content of IDR register, and the query is only possible
later on during the exec phase.
But IDR information is already printed by the dedicated command
apid, making redundant printing it by apsel too.
Being unable to run apsel during initialization, makes also apcsw
command (that depends on apsel) not usable in such phase.

Modify the command apsel to only set the current AP, without making
any transfer to the (possibly not initialized yet) DAP. When run
without parameters, just print the current AP number.
Change mode to COMMAND_ANY to apsel and to apcsw.

Change-Id: Ibea6d531e435d1d49d782de1ed8ee6846e91bfdf
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/4624
Tested-by: jenkins
Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>