soc: swr-mstr: Check if fifo available before bulk write

Check for fifo availability before writing slave registers
during swrm master bulk write so as to prevent swr
overflow, underflow errors.

Change-Id: I97a914cac289b3f1215ccf5c1abec88b959a9f21
Signed-off-by: Vatsal Bucha <vbucha@codeaurora.org>