CN - Couple of bug fixes in USB code. This functions the bugs were in do...

...n't appear to be called by any of the OpenTX code.
When compiling 'next' branch, I noticed a few compiler warnings like this...
usb_dcd_int.c:361:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
Upon investigating the code, it seemed to me that the macro USB_OTG_READ_REG32 was incorrectly being passed the address of pdev->regs.PCGCCTL. I think that pdev->regs.PCGCCTL is already a pointer pointing to the appropriate memory address, so passing the address of this pointer to the macro is a mistake.
This commit removes the compiler warnings, and (I think) fixes a bug.
It looks like the functions that I have altered aren't actually called by the OpenTX code, so I think all I have done is remove the compiler warnings.

Please review the changes and apply them to the OpenTX code if you agree that they fix a problem.