Corrected endianness detection on ppc64el.
Corrected endianness detection on ppc64el.

In common/arch.h, the endianness detection considers all powerpc
architectures as big endian. Since that is not true for ppc64el, I
added a verification that checks other preprocessor macros, only for
ppc cases.

Signed-off-by: Fernando Seiti Furusato <bf54d299d0be315ab3df7a3b7bee9b5b8216a39c@gmail.com>

PKRoma/xrdp,moobyfr/xrdp,moobyfr/xrdp,moobyfr/xrdp,neutrinolabs/xrdp,PKRoma/xrdp,metalefty/xrdp,neutrinolabs/xrdp,PKRoma/xrdp,jsorg71/xrdp,ubuntu-xrdp/xrdp,ubuntu-xrdp/xrdp,metalefty/xrdp,ubuntu-xrdp/xrdp,jsorg71/xrdp,neutrinolabs/xrdp,metalefty/xrdp,jsorg71/xrdp