ldso: Fix Build warnings with common-generic ABI build

ldso: Fix Build warnings with common-generic ABI build

  CC ldso/ldso/ldso.oS
In file included from ./ldso/include/ldso.h:47,
                 from ldso/ldso/ldso.c:33:
./ldso/include/dl-syscall.h:35:1: warning: "S_ISUID" redefined
In file included from ./include/bits/kernel_stat.h:10,
                 from ./ldso/include/dl-syscall.h:31,
                 from ./ldso/include/ldso.h:47,
                 from ldso/ldso/ldso.c:33:
./include/sys/stat.h:163:1: warning: this is the location of the
previous definition
In file included from ./ldso/include/ldso.h:47,
                 from ldso/ldso/ldso.c:33:
./ldso/include/dl-syscall.h:36:1: warning: "S_ISGID" redefined
In file included from ./include/bits/kernel_stat.h:10,
                 from ./ldso/include/dl-syscall.h:31,
                 from ./ldso/include/ldso.h:47,
                 from ldso/ldso/ldso.c:33:
./include/sys/stat.h:164:1: warning: this is the location of the
previous definition

-----------------------------------------------------------------

Cleanly seperated the legacy ABI vs. new ABI scenario.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>