USB: OMAP: ISP1301 needs USB_PHY

The Kconfig entry for USB_OMAP unconditionally selects USB_ISP1301,
which is now only visible when USB_PHY is also enabled.

This adds an appropriate dependency and enables USB_PHY in the omap1
defconfig, avoiding these build warnings:

warning: (USB_OHCI_HCD && USB_OMAP) selects ISP1301_OMAP which has unmet direct dependencies (USB_SUPPORT && USB_PHY && I2C && ARCH_OMAP_OTG)

Also fix a Makefile typo while we're at it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>