[aes_serial] Change order of operations, reduce sleep time
[aes_serial] Change order of operations, reduce sleep time

This commit reorders the execution of some operations when performing SCA
captures (e.g. first provide input data, then start wakeup timer), and it
reduces the sleep time of Ibex from 5000 to 200 clock cycles. This should
slightly improve capture performance.

Signed-off-by: Pirmin Vogel <386a7fc8e7338ed7899b4d9883c0ebec5de81366@lowrisc.org>

lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan