Accton platforms: Add context of installing u-boot in INSTALL

The platforms are including:
- as4600_54t
- as5600_52x
- as5610_52x
- as5710_54x
- as6700_32x
- as6701_32x
- as6710_32x
- as7700_32x

Signed-off-by: Curt Brune <curt@cumulusnetworks.com>
crosstools-ng: back port complib/ppl-0.11.2 with gcc 4.9 patch

This patch back ports an upstream crosstools-ng patch that fixes a
problem building ppl 0.11.2 with gcc 4.9.

See the patch for details about the issue and corrective action.

This patch fixes #104

Testing Done:

Compiled and tested toolchain using Debian stable(wheezy)  (gcc-4.7.2)
Compiled and tested toolchain using Debian testing(jessie) (gcc-4.9.1)