MicroBlaze: Update kernel-features.h for syscalls added in 3.15

MicroBlaze: Update kernel-features.h for syscalls added in 3.15

Now that the MicroBlaze 3.15 kernel has the pselect6, preadv and
pwritev syscalls, this patch updates kernel-features.h so they are
assumed to be present for 3.15 and later kernels.

2014-06-17  Joseph Myers  <joseph@codesourcery.com>

	* sysdeps/unix/sysv/linux/microblaze/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x030f00] (__ASSUME_PSELECT): Do not
	undefine.
	[__LINUX_KERNEL_VERSION >= 0x030f00] (__ASSUME_PREADV): Likewise.
	[__LINUX_KERNEL_VERSION >= 0x030f00] (__ASSUME_PWRITEV): Likewise.

Signed-off-by: David Holsgrove <david.holsgrove@xilinx.com>