x86 mce: Change the method to get the extended MCA information.

x86 mce: Change the method to get the extended MCA information.

Several changes to get the extended MCA information:
a) Use the x86_mcinfo_reserve in mcinfo_extended to reserve buffer
from
   mc_info, instead of using the stack
b) For intel's extended MSR, we don't need write them one
   by one as the MSR are continous
c) We don't need enum mca_extinfo, since we can consider
   the extended MSR as either per bank, or global. Currently
   we add a hook in global data collection, and didn't call
   register intel_get_extended_msrs as callback. Later that
   hook can be replaced by cleaner way

Signed-off-by: Jiang, Yunhong <yunhong.jiang@inte.com>