pe: Add LoongArch definitions

pe: Add LoongArch definitions

Add PE machine types [1] and relocation types [2] for LoongArch to
the current in-repo definitions.

[1] https://learn.microsoft.com/en-us/windows/win32/debug/pe-format#machine-types
[2] https://learn.microsoft.com/en-us/windows/win32/debug/pe-format#base-relocation-types

Signed-off-by: Zhou Yang <zhouyang@loongson.cn>
Signed-off-by: Xiaotian Wu <wuxiaotian@loongson.cn>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>