[ELF] Change std::max<uint64_t> to uint32_t for section alignment
We use uint32_t SectionBase::Alignment and `uint32_t
PhdrEntry::p_align` despite alignments being 64 bits in ELF64.
Fix the std::max template arguments accordingly.
The currently 160-byte InputSection will become 168 bytes if we make SectionBase::Alignment uint64_t.
Differential Revision: https://reviews.llvm.org/D61171