elf: Add new LoongArch reloc types (101 to 108) into elf.h

These reloc types are generated by GNU assembler >= 2.41 for relaxation
support.

Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=57a930e3


Signed-off-by: Xi Ruoyao <xry111@xry111.site>