clear the UULP NPSS GPIO to wakeup interrupt

[hyeonseok-han]

Hi, to clear the UULP NPSS GPIO to wakeup interrupt, i modified as below
from
void sl_si91x_gpio_clear_uulp_npss_wakeup_interrupt(uint8_t npssgpio_interrupt)
{
UULP_GPIO_FSM->GPIO_WAKEUP_REGISTER |= (BIT(npssgpio_interrupt));
}

to

void sl_si91x_gpio_clear_uulp_npss_wakeup_interrupt(uint8_t npssgpio_interrupt)
{
UULP_GPIO_FSM->GPIO_WAKEUP_REGISTER &= ~(BIT(npssgpio_interrupt));
}

[Silabs-Tarun]

this will be fixed in next release.