this quiets warnings from armv6 code [1].
from msdn [2]:
-oldit
Generate ARMv7-style IT blocks. By default, ARMv8-compatible IT blocks
are generated.

a new configuration would be needed for armv8 in any case as the neon
assembly is being built, so removing this should be harmless

[1] A4509: This form of conditional instruction is deprecated
[2] https://msdn.microsoft.com/en-us/library/hh873189.aspx

Change-Id: I4c3b838b52a87401c6daecd83d22ab148ed7c5d9