LoongArch: Support R_LARCH_GOT_PC_{LO12,HI20} in modules

GCC >= 13 and GNU assembler >= 2.40 use these relocations to address
external symbols, so we need to add them.

Let the module loader emit GOT entries for data symbols so we would be
able to handle GOT relocations. The GOT entry is just the data's symbol
address.

In module.lds, emit a stub .got section for a section header entry. The
actual content of the section entry will be filled at runtime by module_
frob_arch_sections().

Tested-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>