x86/intel_rdt: Implement "update" mode when writing schemata file

The schemata file can have multiple lines and it is cumbersome to update
all lines.

Remove code that requires that the user provides values for every resource
(in the right order).  If the user provides values for just a few
resources, update them and leave the rest unchanged.

Side benefit: we now check which values were updated and only send IPIs to
cpus that actually have updates.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Tested-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: ravi.v.shankar@intel.com
Cc: fenghua.yu@intel.com
Cc: peterz@infradead.org
Cc: vikas.shivappa@intel.com
Cc: h.peter.anvin@intel.com
Link: http://lkml.kernel.org/r/1491255857-17213-3-git-send-email-vikas.shivappa@linux.intel.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>