Fix for gold linking tlsdesc into an executable with -pie.

Fix for gold linking tlsdesc into an executable with -pie.
(Also included in this patch is a minor typo fix in gold/ChangeLog.)

When linking the following tlsdesc access sequence into an executable with -pie,

     adrp    x0, :tlsdesc:tls_gd
     ldr     x1, [x0, #:tlsdesc_lo12:tls_gd]
     add     x0, x0, :tlsdesc_lo12:tls_gd
     .tlsdesccall    tls_gd
     blr	     x1
     mrs	     x1, tpidr_el0
     add	     x0, x1, x0
     ldr	     w0, [x0]

current gold-aarch64 backend does tls-desc-gd-to-ie relaxation, into

       adrp    x0, 1000 <__FRAME_END__+0x720>
       ldr     x1, [x0,#4064]	  ;; <=== the target register should be x0
       nop
       nop
       mrs	x1, tpidr_el0
       add	x0, x1, x0
       ldr	w0, [x0]

This code is wrong. The fix changes ldr target register into x0.