Don't install triton on `ppc64le` platform (#16470)

Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

requirements/cpu.txt

@@ -17,4 +17,4 @@ torchvision==0.21.0; platform_machine == "ppc64le"
 datasets # for benchmark scripts
 
 # cpu cannot use triton 3.3.0
-triton==3.2.0
+triton==3.2.0; platform_machine != "ppc64le"