usb: phy: phy-am335x: remove include of regulator/consumer.h

phy-am335x.c doesn't use any interfaces from linux/regulator/consumer.h, so
stop including it.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@kernel.org>