Explicitly use ldur for unaligned offsets; newer versions of
armasm64 implicitly convert ldr to ldur as necessary, but older
versions require it explicitly written out.
This fixes these build errors:
ffmpeg\libavcodec\aarch64\vvc\inter.o.asm(2039) :
error A2518: operand 2: Memory offset must be aligned
ldr s5, [x1, #1]
ffmpeg\libavcodec\aarch64\vvc\inter.o.asm(2250) :
error A2518: operand 2: Memory offset must be aligned
ldr d7, [x1, #2]
Signed-off-by: Martin Storsjö <martin@martin.st>
