Makefile: sign with sbsign instead of pesign
Makefile: sign with sbsign instead of pesign

We hate pesign, there's no Ubuntu package for it and the rest of
our infrastructure uses sbsign.

Change-Id: Ia3c9c50c09edc48b3f747b8e4dce38ad36d172af
Signed-off-by: Andrew Boie <aab045b28152628be6af0e556050d0381fd0a34d@intel.com>
Reviewed-on: https://android.intel.com/181332
Reviewed-by: Abbas, Mohamed <cad1a51755d571b4c23450786ac5dfefb8cd1cfa@intel.com>
Signed-off-by: suyyala <e4be93bc67a65cabdb987ccfb84f04770b1752f6@intel.com>

android-ia/platform_external_uefi_shim,android-ia/platform_external_uefi_shim,CyanogenMod/android_external_uefi_shim,CyanogenMod/android_external_uefi_shim,CyanogenMod/android_external_uefi_shim,android-ia/platform_external_uefi_shim