video: ivybridge_igd: Fix compiler warning

Fix build warning in drivers/video/ivybridge_igd.c with gcc 7.3.0:

  warning: 'ivb_pm_gt2' defined but not used [-Wunused-const-variable=]

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
1 file changed