Add MadtLocalApicNmi (type 0x4), MadtLapicAddressOverride (type 0x5), and MadtLocalX2ApicNmi (type 0xA) structs with compile-time size assertions. Add enum variants and iterator cases for all three. Implement set_lvt_nmi() on LocalApic for both xAPIC (LINT0/LINT1 at offsets 0x350/0x360) and x2APIC (MSRs 0x835/0x836) with NMI delivery mode, polarity, and trigger mode from MADT flags. Process NMI entries in x86.rs MADT loop to configure per-CPU LVT NMI registers. Parse and log LAPIC address override (64-bit) for future use.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
vasilito
01a6bc8d2e