allwinner: Leave CPU power alone during BL31 setup

Disabling secondary CPUs during boot is unnecessary because the other
CPUs are already in reset, and it saves an entirely insignificant amount
of power. Let's remove this bit of code that was added mostly "because
we can", and along with it remove an unconditional dependency on the CPU
ops functions.
Signed-off-by: Samuel Holland <samuel@sholland.org>
Change-Id: Ia77a1b722da6ba989c3992b656a6cde3f2238fd7

plat/allwinner/common/sunxi_bl31_setup.c

@@ -100,9 +100,6 @@ void bl31_early_platform_setup2(u_register_t arg0, u_register_t arg1,
 	bl33_image_ep_info.spsr = SPSR_64(MODE_EL2, MODE_SP_ELX,
 					  DISABLE_ALL_EXCEPTIONS);
 	SET_SECURITY_STATE(bl33_image_ep_info.h.attr, NON_SECURE);
-
-	/* Turn off all secondary CPUs */
-	sunxi_disable_secondary_cpus(read_mpidr());
 }
 
 void bl31_plat_arch_setup(void)