ARM64: implement TASK_SIZE_OF

include/linux/sched.h implements TASK_SIZE_OF as TASK_SIZE if it
is not set by the architecture headers.  TASK_SIZE uses the
current task to determine the size of the virtual address space.
On a 64-bit kernel this will cause reading /proc/pid/pagemap of a
64-bit process from a 32-bit process to return EOF when it reads
past 0xffffffff.

Implement TASK_SIZE_OF exactly the same as TASK_SIZE with
test_tsk_thread_flag instead of test_thread_flag.

Change-Id: I55c53e5c108757d5f6b6ce1c9f78dfb220e29502
Signed-off-by: Colin Cross <ccross@android.com>
Git-repo: git://codeaurora.org/quic/la/kernel/tegra.git


Git-commit: b21cba50d8ee47e6b4a6bbef0d61852bde9ca04d
Signed-off-by: Trilok Soni <tsoni@codeaurora.org>