soc: qcom: add Embedded USB Debugger (EUD) driver

The EUD (Embedded USB Debugger) is a mini-USB hub implemented
on chip to support the USB-based debug and trace capabilities.

The driver notifies USB driver on USB attach or detach event
generated when vbus interrupt happens and notifies PMIC driver
on charger enable or disable event when charger interrupt
happens via EXTCON.

The driver handles COM Port Tx and Rx interrupts by using standard
serial driver interface, pets EUD when safe mode warning interrupt
received.

Also, driver provides an interface via sysfs to enable/disable EUD.

CRs-Fixed: 1060581
Change-Id: Iae9bd9500efc8880e14848abee60f96f4b849b90
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>