Backport perf makefile fix to linux-6.6.y

Hello stable team,

could you please backport commit 440cf77625e3 ("perf: build: Setup PKG_CONFIG_LIBDIR for cross compilation") to linux-6.6.y ?

Its absence prevents some people from building the perf tool in cross-compile environment with this kernel. The patch applies cleanly on linux-6.6.y

Thanks,

Alexis