modphp: enable endian check

Previously, modphp estimates endian on host rather than checks it on
target. If the host is little-endian and the target is big-endian,
modphp claims that endian is little. As a result, a memory location
that it is not allowed to access when calling libphp5.so module on
target. It will occur segmentation fault.
This patch enables endian check support for modphp.

Signed-off-by: Chong Lu <Chong.Lu@windriver.com>
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>