rsi: rename variable in_sdio_litefi_irq

The variable in_sdio_litefi_irq is renamed to sdio_irq_task,
as it is more relevant here.

Signed-off-by: Karun Eagalapati <karun256@gmail.com>
Signed-off-by: Amitkumar Karwar <amit.karwar@redpinesignals.com>
Signed-off-by: Prameela Rani Garnepudi <prameela.j04cs@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>