usb: phy: qusb: Add support to read TUNE2 using EFUSE register

QUSB_PHY_TUNE2 parameter's high nibble value may vary across
different devices. It needs to be read through EFUSE based
register. This change adds support which reads EFUSE based register,
and calculate TUNE2 parameter's high nibble value. It also requires
number of bits to use and starting position of bit with EFUSE
register to calculate this value. In case, EFUSE register based
value is zero, it uses 0xB as default high nibble value with low
nibble value (0x3 which always default value).

CRs-Fixed: 705188
Change-Id: I1a530e34342ea3a897e7f6cb80957af9c1fe3bf5
Signed-off-by: Mayank Rana <mrana@codeaurora.org>