[AMDGPU] Make vop1 disassembler tests use strict-whitespace

NFC.
The whitespace needs to be consistently formatted in some manner. Might as well
use -strict-whitespace as the standard.
Adds -strict-whitespace to RUN lines and adjust CHECK line space padding
accordingly.

Also test REAL16 and FAKE16 CHECK lines with wave64.

Author: Sisyph