soc: fsl: qe: use qe_ic_cascade_{low, high}_mpic also on 83xx

The *_ipic and *_mpic handlers are almost identical - the only
difference is that the latter end with an unconditional
chip->irq_eoi() call. Since IPIC does not have ->irq_eoi, we can
reduce some code duplication by calling irq_eoi conditionally.

This is similar to what is already done in mpc8xxx_gpio_irq_cascade().

This leaves the functions slightly misnamed, but that will be fixed in
a subsequent patch.

Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

arch/powerpc/platforms/83xx/misc.c

@@ -102,7 +102,7 @@ void __init mpc83xx_qe_init_IRQ(void)
 		if (!np)
 			return;
 	}
-	qe_ic_init(np, 0, qe_ic_cascade_low_ipic, qe_ic_cascade_high_ipic);
+	qe_ic_init(np, 0, qe_ic_cascade_low_mpic, qe_ic_cascade_high_mpic);
 	of_node_put(np);
 }