Revert "arm64: spinlock: Drop the prfm from arch_spin_trylock"

This reverts commit 00d37423.

Causes the following assembler errors:
/tmp/spinlock_debug-15a9d8.s:441: Error: attempt to move .org backwards

The reverted commit is an out of tree patch that does not exist in
4.14.y upstream.  Mainline has outright removed the arch_spin_trylock()
function in this translation units.

See also from mainline:
commit a4c1887d4c14 ("locking/arch: Remove dummy
arch_{read,spin,write}_lock_flags() implementations")
commit c11090474d70 ("arm64: locking: Replace ticket lock implementation
with qspinlock")

Bug: 117152549
Change-Id: I3eb40e5d18ed22c4e3ff1d2b8707e784067aabac
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Alexander Winkowski <dereference23@outlook.com>