rsi: Optimise sdio claim and release host

SDIO host is already claimed in our interrupt handler. Some lower
level APIs claims host while performing SDIO read or write operations.
Let's use sdio_irq_task variable to check if we are in interrupt
context and claim/release the host accordingly.

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>