intel/perf: Use a function to initialize perf counters

intel/perf: Use a function to initialize perf counters

And specifically mark it with ATTRIBUTE_NOINLINE. Otherwise it will be
inlined and actually slightly increase code size.

Cuts 505 KiB from iris_dri.so and libvulkan_intel.so.

   text    data     bss     dec     hex filename
1538720       0       0 1538720  177aa0 meson-generated_.._intel_perf_metrics.c.o (before)
 926811   43200       0  970011   ecd1b meson-generated_.._intel_perf_metrics.c.o (after)

   text    data     bss     dec     hex filename
14751700 365708  210004 15327412 e9e0b4 iris_dri.so (before)
14190852 408908  210004 14809764 e1faa4 iris_dri.so (after)

   text    data     bss     dec     hex filename
8744913  214264   22820 8981997  890ded libvulkan_intel.so (before)
8184097  257464   22820 8464381  8127fd libvulkan_intel.so (after)

Relocations increase because the counter initializations are moved from
code (in .text) to pointers (in .text) to .rodata, which require
relocations.

relinfo:
iris_dri.so (before): 15605 relocations, 15385 relative (98%), 452 PLT entries, 1 for local syms (0%), 0 users
iris_dri.so (after) : 17765 relocations, 17545 relative (98%), 452 PLT entries, 1 for local syms (0%), 0 users

libvulkan_intel.so (before):  8560 relocations, 4829 relative (56%), 355 PLT entries, 1 for local syms (0%), 0 users
libvulkan_intel.so (after) : 10720 relocations, 6989 relative (65%), 355 PLT entries, 1 for local syms (0%), 0 users

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15237>