This fixes the following build error with GCC 11:

    In function ‘snb_wm_latency_quirk’,
        inlined from ‘ilk_setup_wm_latency’ at drivers/gpu/drm/i915/intel_pm.c:3109:3,
        inlined from ‘intel_init_pm’ at drivers/gpu/drm/i915/intel_pm.c:7695:3:
    drivers/gpu/drm/i915/intel_pm.c:3058:9: error: ‘intel_print_wm_latency’ reading 16 bytes from a region of size 10 [-Werror=stringop-overread]
     3058 |         intel_print_wm_latency(dev_priv, "Primary", dev_priv->wm.pri_latency);
          |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    drivers/gpu/drm/i915/intel_pm.c: In function ‘intel_init_pm’:
    drivers/gpu/drm/i915/intel_pm.c:3058:9: note: referencing argument 3 of type ‘const u16 *’ {aka ‘const short unsigned int *’}
    drivers/gpu/drm/i915/intel_pm.c:2995:13: note: in a call to function ‘intel_print_wm_latency’
     2995 | static void intel_print_wm_latency(struct drm_i915_private *dev_priv,
          |             ^~~~~~~~~~~~~~~~~~~~~~

As far as I can tell, we don't actually need 8 elements except on SKL
and that uses dev_priv->wm.skl_latency which has enough.
Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210413173259.472405-1-jason@jlekstrand.netSigned-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>