freedreno/ir3: fix linkage::var size
freedreno/ir3: fix linkage::var size

It should actually be 32 for a4xx/a5xx.. we still only advertise 16 but
for a5xx the linkage map includes position/psize.

Signed-off-by: Rob Clark <915c10c999604870200b6defbe633d857c856ca0@gmail.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler