hw/ppc/openpic: Do not open-code ROUND_UP() macro

While reviewing, the ROUND_UP() macro is easier to figure out.
Besides, the comment confirms we want to round up here.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20230523061546.49031-1-philmd@linaro.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

include/hw/ppc/openpic.h

@@ -55,7 +55,7 @@ typedef enum IRQType {
  * Round up to the nearest 64 IRQs so that the queue length
  * won't change when moving between 32 and 64 bit hosts.
  */
-#define IRQQUEUE_SIZE_BITS ((OPENPIC_MAX_IRQ + 63) & ~63)
+#define IRQQUEUE_SIZE_BITS ROUND_UP(OPENPIC_MAX_IRQ, 64)
 
 typedef struct IRQQueue {
     unsigned long *queue;