usb: gadget: f_fs: Add support for IPC logging

Log function entry and exit and dump relevant values
into IPC log buffer. This allows to debug various
race conditions and stability issues.

Allow this to be enabled with CONFIG_USB_F_FS_IPC_LOGGING
which is dependent on CONFIG_QGKI.

Change-Id: I15011d79fc2f054e64f8bbd1f8f5db8944b46ada
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>
Signed-off-by: Mayank Rana <mrana@codeaurora.org>
Signed-off-by: Jack Pham <jackp@codeaurora.org>