Revert "x86/microcode: Kill refresh_fw"

Intel inclusion
category: feature
feature: Backport Intel In Field Scan(IFS) multi-blob images support
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I6L337


CVE: N/A
Reference: N/A

Intel-SIG: Revert commit 8b0c0efc ("x86/microcode: Kill refresh_fw")

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This reverts commit 8b0c0efc.

This revert is to recover old microcode interface /dev/cpu/microcode.

Signed-off-by: Aichun Shi <aichun.shi@intel.com>