bluetooth: nordic: lll: Use direct ISR when applicable

This commit updates nordic lll controller to use
IRQ_DIRECT_CONNECT where applicable instead of
using IRQ_CONNECT with ISR_FLAG_DIRECT.

(cherry picked from commit 8f98b8b)

Original-Signed-off-by: Radosław Koppel <radoslaw.koppel@nordicsemi.no>
GitOrigin-RevId: 8f98b8b
Change-Id: I8e9352fa72796d0f91a4b42f93f4e43fa7954ff2
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/zephyr/+/5280230
Reviewed-by: Al Semjonovs <asemjonovs@google.com>
Tested-by: Al Semjonovs <asemjonovs@google.com>
Tested-by: ChromeOS Prod (Robot) <chromeos-ci-prod@chromeos-bot.iam.gserviceaccount.com>
Commit-Queue: Al Semjonovs <asemjonovs@google.com>

subsys/bluetooth/controller/ll_sw/nordic/lll/lll.c

@@ -221,8 +221,13 @@ int lll_init(void)
  radio_nrf5_isr, IRQ_CONNECT_FLAGS);
  IRQ_CONNECT(RTC0_IRQn, CONFIG_BT_CTLR_ULL_HIGH_PRIO,
  rtc0_nrf5_isr, NULL, 0);
+#if defined(CONFIG_BT_CTLR_ZLI)
+ IRQ_DIRECT_CONNECT(HAL_SWI_RADIO_IRQ, CONFIG_BT_CTLR_LLL_PRIO,
+ swi_lll_nrf5_isr, IRQ_CONNECT_FLAGS);
+#else
  IRQ_CONNECT(HAL_SWI_RADIO_IRQ, CONFIG_BT_CTLR_LLL_PRIO,
  swi_lll_nrf5_isr, NULL, IRQ_CONNECT_FLAGS);
+#endif
 #if defined(CONFIG_BT_CTLR_LOW_LAT) || \
  (CONFIG_BT_CTLR_ULL_HIGH_PRIO != CONFIG_BT_CTLR_ULL_LOW_PRIO)
  IRQ_CONNECT(HAL_SWI_JOB_IRQ, CONFIG_BT_CTLR_ULL_LOW_PRIO,