ARM: EXYNOS: Remove wrongly placed usb2.0 PHY_CFG definition from PMU_REG

EXYNOS5_USB_CFG macro should actually point to USB20PHY_CFG system
register (base addr + 0x230). It's wrongly placed in regs-pmu.
Actual register at offset 0x230 in PMU is SEQ_TRANSITION4.

Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
Reviewed-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>