Bluetooth: HID: Add support for building hid drivers

This patch adds support for enabling uhid driver in kernel which
provides interface for user space hid module to interact with
hid drivers of kernel. Without support for uhid driver, Bluetooth
HID functionality is broken completely. Also support for vendor
hid drivers is enabled so that HID profile can be connected with
these HID devices.

Change-Id: If56742a9c6b6c4ef774da6e83d57aee56bf28842
CRs-Fixed: 553571
Signed-off-by: Hemant Gupta <hemantg@codeaurora.org>