libc: posix_fadvise: restore implementation for xtensa
libc: posix_fadvise: restore implementation for xtensa

Commit ee84b8b400 (linux: posix_fadvise: use new SYSCALL_ALIGN_64BIT)
removed posix_fadvise implementation for xtensa, since xtensa does not
define __NR_fadvise64. Reuse the ARM support code to restore xtensa support.

This commit is based Mike Frysinger's suggested patch.

Cc: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@gentoo.org>
Signed-off-by: Baruch Siach <53ccad33e0625915318fb3bc832e5c1c413d1294@tkos.co.il>
Signed-off-by: Bernhard Reutner-Fischer <ce1ac9e9ad16abccd7821f371ad381197b4768ac@gmail.com>

ffainelli/uClibc,majek/uclibc-vx32,ffainelli/uClibc,foss-for-synopsys-dwc-arc-processors/uClibc,kraj/uclibc-ng,groundwater/uClibc,kraj/uclibc-ng,brgl/uclibc-ng,hjl-tools/uClibc,brgl/uclibc-ng,brgl/uclibc-ng,ffainelli/uClibc,ffainelli/uClibc,wbx-github/uclibc-ng,groundwater/uClibc,majek/uclibc-vx32,kraj/uClibc,hjl-tools/uClibc,wbx-github/uclibc-ng,groundwater/uClibc,groundwater/uClibc,kraj/uClibc,groundwater/uClibc,hjl-tools/uClibc,kraj/uclibc-ng,foss-for-synopsys-dwc-arc-processors/uClibc,wbx-github/uclibc-ng,ffainelli/uClibc,kraj/uClibc,foss-for-synopsys-dwc-arc-processors/uClibc,wbx-github/uclibc-ng,hjl-tools/uClibc,kraj/uclibc-ng,hjl-tools/uClibc,foss-for-synopsys-dwc-arc-processors/uClibc,kraj/uClibc,majek/uclibc-vx32,majek/uclibc-vx32,brgl/uclibc-ng