igb: fix warning about unused function
igb: fix warning about unused function

This patch fixes a warning about unused function when CONFIG_PM_SLEEP
is not selected in the kernel config:

igb_main.c: warning: `igb_suspend` defined but not used [W-unused-function]

Signed-off-by: Emil Tantilov <7bb77ce8696ed668ba78a49cc3445dd5ee9fe4b8@intel.com>
Tested-by: Aaron Brown <4723df1d9a4136f7b76e1bf6434e33afc91d2139@intel.com>
Signed-off-by: Jeff Kirsher <87e35f5be20bb3e67f4ba6b86f5f6be3085b1b3a@intel.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas