arm64: Add __NR_* definitions for compat syscalls

This patch adds __NR_* definitions to asm/unistd32.h, moves the
__NR_compat_* definitions to asm/unistd.h and removes all the explicit
unistd32.h includes apart from the one building the compat syscall
table. The aim is to have the compat __NR_* definitions available but
without colliding with the native syscall definitions (required by
lib/compat_audit.c to avoid duplicating the audit header files between
native and compat).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Git-commit: cfc7e99e9e3900056028a7d90072e9ea0d886f8d
Git-repo: https://android.googlesource.com/kernel/common.git


[imaund@codeaurora.org: Resolved context conflicts]
Signed-off-by: Ian Maund <imaund@codeaurora.org>

Change-Id: Ie8905be2828c222da7b6753fc0f8ab69c57edaac
Signed-off-by: Nirmal Abraham <nabrah@codeaurora.org>