soc: qcom: dfc: add query after existing powersave mode

Added query after exiting powersave mode to get grant information.
Also limit the default grant to 1 byte to reduce packets sent before
getting grant.

Change-Id: Ia2fd5a50e05e44a403779f701b27981496dfca45
Acked-by: Ning Cai <ncai@qti.qualcomm.com>
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>