jtagv8: do not lock os double lock in debug save path

Locking the OS Double Lock in Jtag Debug save sequence and
also subsequently unlocking it in restore sequence cause
issues when A57 cores are power collapsed. Provide a temporary
fix by not locking this register during Jtag Debug save path.

Change-Id: I870e593024bd2cabd4eee2bee1f1869f439a134a
Signed-off-by: Aparna Das <adas@codeaurora.org>