soc: arm: nxp: fix USB w/ SPEED_OPTIMIZATIONS

Fix USB w/ SPEED_OPTIMIZATIONS for LPC55xxx SoCs
Root cause was non-volatile register access,
which could get optimized by the compiler
(by -fschedule-insns, specifically)

Signed-off-by: Maxime Vincent <maxime@veemax.be>
(cherry picked from commit f86f98f)

soc/nxp/lpc/lpc55xxx/soc.c

@@ -228,7 +228,7 @@ static ALWAYS_INLINE void clock_init(void)
 	 * According to reference mannual, device mode setting has to be set by access
 	 * usb host register
 	 */
-	*((uint32_t *)(USBFSH_BASE + 0x5C)) |= USBFSH_PORTMODE_DEV_ENABLE_MASK;
+	USBFSH->PORTMODE |= USBFSH_PORTMODE_DEV_ENABLE_MASK;
 	/* disable usb0 host clock */
 	CLOCK_DisableClock(kCLOCK_Usbhsl0);
 
@@ -244,12 +244,12 @@ static ALWAYS_INLINE void clock_init(void)
 	/* enable usb1 host clock */
 	CLOCK_EnableClock(kCLOCK_Usbh1);
 	/* Put PHY powerdown under software control */
-	*((uint32_t *)(USBHSH_BASE + 0x50)) = USBHSH_PORTMODE_SW_PDCOM_MASK;
+	USBHSH->PORTMODE = USBHSH_PORTMODE_SW_PDCOM_MASK;
 	/*
 	 * According to reference manual, device mode setting has to be set by
 	 * access usb host register
 	 */
-	*((uint32_t *)(USBHSH_BASE + 0x50)) |= USBHSH_PORTMODE_DEV_ENABLE_MASK;
+	USBHSH->PORTMODE |= USBHSH_PORTMODE_DEV_ENABLE_MASK;
 	/* disable usb1 host clock */
 	CLOCK_DisableClock(kCLOCK_Usbh1);