Add new relocs number for tls le relax.
include/ChangeLog:
* elf/loongarch.h:
(RELOC_NUMBER (R_LARCH_TLS_LE_HI20_R, 121)): New relocs number.
(RELOC_NUMBER (R_LARCH_TLS_LE_ADD_R, 122)): Likewise.
(RELOC_NUMBER (R_LARCH_TLS_LE_LO12_R, 123)): Likewise.