arm_mpam: resctrl: Implement arch hook to set up the default CLOSID

Since the allocation of CLOSIDs can now depend on parameters such
as resctrl filesystem mount options that are not available at arch
driver init time, all MPAM resource allocations need to be
reprogrammed when resctrl is mounted.

Implement resctrl_arch_init_domains() so that resctrl will now
reprogram the default CLOSID's resource allocations at filesystem
mount time, in the same way as when creating a new resctrl control
group.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>