Since we are compiling for a single chipset that is known to support LSE,
the system_uses_lse_atomics() static branch can be eliminated entirely.
Therefore, make system_uses_lse_atomics() always true to always use LSE
atomics, and update ARM64_LSE_ATOMIC_INSN() users to get rid of the extra
nops used for alternatives patching at runtime.
This reduces generated code size by removing LL/SC atomics, which improves
instruction cache footprint.
Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>