toolchain: Bump ARC tools to arc-2017.03 release

This commit finally bumps ARC toolchain to arc-2017.03 release.
More info on this release could be found here:
https://github.com/foss-for-synopsys-dwc-arc-processors/toolchain/releases/tag/arc-2017.03

Note mentioned above web-page is not yet populated but should be very soon.
As a safe fall-back interested could refer to RC2 page here:
https://github.com/foss-for-synopsys-dwc-arc-processors/toolchain/releases/tag/arc-2017.03-rc2



Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>