USB host:  Remove getdevinfo() method.  Rename hub structure to hubport structure.  Get port and function address from hub port structure vs. parameters and other structures.

Conflicts:
	nuttx/include/nuttx/usb/usbhost.h

STM32 F1 RTC Counter:  Now need to enable backup domain write access when setting the time.  From Darcy Gong

Bring in USB hub-related files from https://github.com/kaushalparikh/nuttx.  This is the work of Kaushal Parikh.  This initial commit is incomplete.  This is quite a bit more hub logic that needs to come in before the port is complete.

Fix an error introduced into stm32_pwr_enablebkp().  That function must preserve the previous state of backup domain access on return.