aco: take LDS into account when calculating num_waves

aco: take LDS into account when calculating num_waves

pipeline-db (Vega):
SGPRS: 344 -> 344 (0.00 %)
VGPRS: 424 -> 524 (23.58 %)
Spilled SGPRs: 84 -> 80 (-4.76 %)
Spilled VGPRs: 0 -> 0 (0.00 %)
Private memory VGPRs: 0 -> 0 (0.00 %)
Scratch size: 0 -> 0 (0.00 %) dwords per thread
Code Size: 52812 -> 52484 (-0.62 %) bytes
LDS: 135 -> 135 (0.00 %) blocks
Max Waves: 56 -> 53 (-5.36 %)

v2: consider WGP, rework to be clearer and apply the
    "maximum 16 workgroups per CU" limit properly
v2: use "SIMD" instead of "EU"
v2: fix spiller by introducing "Program::max_waves"
v2: rename "lds_size" to "lds_limit"
v3: make max_waves actually independant of register usage
v3: fix issue where max_waves was way too high
v3: use DIV_ROUND_UP(a, b) instead of max(a / b, 1)
v3: rename "workgroups_per_cu" to "workgroups_per_cu_wgp"
v4: fix typo from "workgroups_per_cu" rename

Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev> (v3)