properties: increase shutdown timeout to 10s

By default, we have:

• 3s to thermal shutdown/reboot
• 6s to cleanly shutdown/reboot

The reboot procedure is quite CPU intensive, we have stop all processes, then unmount lots of partitions and APEXes.

The process stopping already takes over 3s:

[  296.122460][    T1] init: Ready to unmount apexes. So far shutdown sequence took 3388ms

Unmounting the APEXes takes longer than 3s. Because of this, we always hit the time-out during reboot, which logs the following warning:

    [  299.213450][    T1] init: umount timeout, last resort, kill all and try
    [  299.528401][    T1] sysrq: Show backtrace of all active CPUs
    [  299.534068][    T1] sysrq: CPU0:
    [  299.537287][    T1] Call trace:
    [  299.540428][    T1]  dump_backtrace+0xfc/0x1f8
    [  299.544910][    T1]  sysrq_handle_showallcpus+0x94/0x13c
    [  299.550232][    T1]  __handle_sysrq+0x108/0x208
    [  299.554765][    T1]  write_sysrq_trigger+0xfc/0x160
    [  299.559642][    T1]  proc_reg_write+0xf8/0x16c
    [  299.564095][    T1]  vfs_write+0x138/0x34c
    [  299.568200][    T1]  ksys_write+0x7c/0xe8
    [  299.572208][    T1]  __arm64_sys_write+0x20/0x2c
    [  299.576822][    T1]  invoke_syscall+0x5c/0x114
    [  299.581271][    T1]  el0_svc_common+0xb8/0xf8
    [  299.585627][    T1]  do_el0_svc+0x30/0xb8
    [  299.589637][    T1]  el0_svc+0x28/0x9c
    [  299.593407][    T1]  el0t_64_sync_handler+0x7c/0xe4
    [  299.598286][    T1]  el0t_64_sync+0x1a4/0x1a8
    [  299.602669][    C1] sysrq: CPU1: backtrace skipped as idling
    [  299.602669][    C3] sysrq: CPU3: backtrace skipped as idling
    [  299.602669][    C2] sysrq: CPU2: backtrace skipped as idling
    [  299.602724][    T1] sysrq: Show Blocked State
    [  299.624165][    T1] sysrq: Kill All Tasks

Remove the warning by increasing the reboot timer to 10s.

Signed-off-by: Mattijs Korpershoek mkorpershoek@baylibre.com