ArmPkg/BdsLib: Send RemainingDevicePath to PXE Load File protocol

ArmPkg/BdsLib: Send RemainingDevicePath to PXE Load File protocol

Load File protocol requires remaining device path rather than whole
device path. For PXE, it actually requires end node device path only,
or else invalid parameter will be returned directly.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Heyi Guo <heyi.guo@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19148 6f19259b-4bc3-4df7-8a09-765794883524