webp: kill CPU features and use upstream NEON detection

* bionic's cpu-features.h is dead, so use __ARM_NEON__

* fixes AArch32 compile

Test: mm

Change-Id: I342b2e3bd44fcd2b86a80b45a31dadd9b74189a7
Signed-off-by: Jake Weinstein <xboxlover360@gmail.com>
6 files changed