x86/resctrl: Expand resctrl_arch_update_domains()'s msr_param range

resctrl_arch_update_domains() specifies the one closid that has been
modified and needs copying to the hardware.

resctrl_arch_update_domains() takes a struct rdt_resource and a closid
as arguments, but copies all the staged configurations for that closid
into the ctrl_val[] array.

resctrl_arch_update_domains() is called once per schema, but once the
resources and domains are merged, the second call of a L2CODE/L2DATA
pair will find no staged configurations, as they were previously
applied. The msr_param of the first call only has one index, so would
only have update the hardware for the last staged configuration.

To avoid a second round of IPIs when changing L2CODE and L2DATA in one
go, expand the range of the msr_param if multiple staged configurations
are found.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lkml.kernel.org/r/20210728170637.25610-24-james.morse@arm.com