busybox udhcpc: Make hostname sanitization be optional

The hostname leading with digit passed by DHCP opt 66 is invalid
because it is constrained by RFC-1035.

As mentioned in networking/udhcp/Config.src:
    udhcpc will check some options (such as option 12 -
    hostname) and if they don't look like valid hostnames
    (for example, if they start with dash or contain spaces),
    they will be replaced with string "bad" when exporting
    to the environment.

The invalid hostname will be replaced with string "bad".  It causes
ONIE use the "bad" hostname to fetch installer.  This patch will
disable the check and pass TFTP server name to ONIE without any
alteration.

Ref:
http://git.busybox.net/busybox/commit/?id=85090c162b322a4ffe53d251e59bbfc212a829ee

Signed-off-by: david_yang <david_yang@accton.com>
Make busybox 1.20.2 default

Fixes #47

1.20.0 has a nasty bug, which is fixed in 1.20.2:

https://bugs.busybox.net/show_bug.cgi?id=5282

  Result of variable substitution in right hand side of I/O
  redirection causes trailing garbage byte.

Signed-off-by: Curt Brune <curt@cumulusnetworks.com>
linux-fsl-sdk-v1.5: Fix buffer overwrite issue in fsl espi

When the fsl espi driver is enabled, it has probability to cause
kernel exception.  In Accton AS6700_32X, we inject broadcast
packets into the management port steadily, the exception will
happen after user inputs the 'reboot' command to the kernel.

Ref:
- http://www.spinics.net/lists/linux-spi/msg01076.html

Signed-off-by: Curt Brune <curt@cumulusnetworks.com>
Accton AS6700_32X: Add to support ONIE

Signed-off-by: Curt Brune <curt@cumulusnetworks.com>