[AAELF64] Remove spaces in Relocation codes

A number of relocation codes such as R\_<CLS>\_TLSGD\_ ADR\_PREL21
have a space in the name after an _. These look to have been here
since the initial rst commit. It is possible that this was inherited
from the MS Word originals.

Enforce consistency be removing all the spaces.

Fixes ARM-software#308