ARM: omap2: remove unnecessary boot_lock

The boot_lock is something that was required for ARM development
platforms to ensure that the delay calibration worked properly.  This
is not necessary for modern platforms that have better bus bandwidth
and do not need to calibrate the delay loop for secondary cores.
Remove the boot_lock entirely.

Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>