This patch adds translation from CPU to DMA addresses, which is required for
proper operation on certain architectures like MIPS.

This patch also fixes the bug introduced by 4350744bf5 "usb: ehci-hcd: port
periodic transactions implementation from the u-boot", which is still present
in the original U-Boot code:

	td->qt_buffer[0] =
		cpu_to_hc32((unsigned long)buffer + i * elementsize);
	td->qt_buffer[1] =
		cpu_to_hc32((td->qt_buffer[0] + 0x1000) & ~0xfff);
	...

In case of a big-endian CPU 0x1000 is added to the byte-swapped value
`td->qt_buffer[0]`, the result is byte swapped once again and stored to
`td->qt_buffer[1]`. This results in erroneous values being stored in
`td->qt_buffer[1..4]`.

N.B.: This patch needs some testing on architectures different from MIPS.

Signed-off-by: Peter Mamonov <pmamonov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>