Remove the legacy firmware driver parsing logics from `ParseSecureBootState`

[yawangwang]

This function parses firmware driver event logs irrelevant to secure boot

go-eventlog/extract/secureboot.go

Line 108 in cec9cd6

func ParseSecurebootState(events []tcg.Event, registerCfg registerConfig) (*SecurebootState, error) {

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Now with the new method EfiDriverState extracting EFI driver information, the duplicated firmware driver parsing logics should be removed from ParseSecureBootState