RFR: 8167584: aarch32: use "arm" for os.arch system property

[Alex Kashchenko]

Hi,

Please review and sponsor small autoconf patch that changes "os.arch" 
system property from "aarch32" to "arm":

  - issue: https://bugs.openjdk.java.net/browse/JDK-8167584
  - webrev: 
http://cr.openjdk.java.net/~akasko/aarch32/jdk8u/8167584/webrev.00/

Problem was initially reported for Fedora openjdk-aarch32 package by 
Eclipse developers, and I was asked on RH-internal list to bring the 
change upstream.

SWT uses this property to find out the arch and expects to have "arm" on 
armv7. I checked other jdks (openjdk7-asmjit, openjdk8-zero, oracle 
jdk8, openjdk9-arm3264) - all of them return "arm" for os.arch.

Proposed change shouldn't affect anything except "os.arch" property. It 
applied to platform.m4, generated-configure.sh script was re-generated.

-- 
-Alex