[LoongArch] Use R_LARCH_ALIGN without symbol as much as possible (#93775)

To support the third parameter of the alignment directive, R_LARCH_ALIGN
relocations need a non-zero symbol index.
In many cases we don't need the third parameter and can set the symbol
index to 0.
This patch will remove a lot of .Lla-relax-align* symbols and mitigate
the size regression due to
https://github.com/llvm/llvm-project/pull/72962

.

Co-authored-by: Jinyang He <hejinyang@loongson.cn>
Co-authored-by: Weining Lu <luweining@loongson.cn>