nptl: Remove nptl/sysdeps/generic directory from include list

All archs have now moved their generic sysdep.h header from
sysdeps/generic to sysdeps/common directory, so it is possible
to remove the sysdeps/generic directory from the include list.

Signed-off-by: Carmelo Amoroso <carmelo.amoroso@st.com>

Rules.mak

@@ -669,7 +669,6 @@ PTINC:= -I$(top_builddir)$(PTDIR)					\
 	-I$(top_srcdir)$(PTDIR)/sysdeps/$(TARGET_ARCH)			\
 	-I$(top_builddir)$(PTDIR)/sysdeps/unix/sysv/linux		\
 	-I$(top_srcdir)$(PTDIR)/sysdeps/unix/sysv/linux			\
-	-I$(top_srcdir)$(PTDIR)/sysdeps/generic				\
 	-I$(top_srcdir)$(PTDIR)/sysdeps/pthread				\
 	-I$(top_srcdir)$(PTDIR)/sysdeps/pthread/bits			\
 	-I$(top_srcdir)ldso/ldso/$(TARGET_ARCH)				\