drm/i915: Fix undefined behavior due to shift overflowing the constant

Fix:

  In file included from <command-line>:0:0:
  drivers/gpu/drm/i915/gt/uc/intel_guc.c: In function ‘intel_guc_send_mmio’:
  ././include/linux/compiler_types.h:352:38: error: call to ‘__compiletime_assert_1047’ \
  declared with attribute error: FIELD_PREP: mask is not constant
    _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)

and other build errors due to shift overflowing values.

See https://lore.kernel.org/r/YkwQ6%2BtIH8GQpuct@zn.tnic for the gory
details as to why it triggers with older gccs only.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: intel-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
5 files changed