x86/mce: Cleanup bank processing on init

x86/mce: Cleanup bank processing on init

Unify the bank preparation into __mcheck_cpu_init_clear_banks(), rename that
function to what it does now - prepares banks. Do this so that generic and
vendor banks init goes first so that settings done during that init can take
effect before the first bank polling takes place.

Move __mcheck_cpu_check_banks() into __mcheck_cpu_init_prepare_banks() as it
already loops over the banks.

The MCP_DONTLOG flag is no longer needed, since the MCA polling function is
now called only if boot-time logging should be done.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com>
Reviewed-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/20250825-wip-mca-updates-v5-5-865768a2eef8@amd.com