doc: dt-binding: mxs-usb-phy: fix fsl,tx-cal-45-dn-ohms max and min value

According to spec:
0000 +19.95%
....
1111 -21.68%

45 * (1 + 19.95%) = 53.9775
45 * (1 - 21.68%) = 35.244

Chanege fsl,tx-cal-45-dn-ohms and fsl,tx-cal-45-dp-ohms range to [35-54]
from [30-55]

Acked-by: Krzysztof Kozlowski <[e-mail]>
Signed-off-by: Frank Li <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/devicetree/bindings/phy/mxs-usb-phy.txt

···
 - fsl,anatop: phandle for anatop register, it is only for imx6 SoC series
 
 Optional properties:
-- fsl,tx-cal-45-dn-ohms: Integer [30-55]. Resistance (in ohms) of switchable
+- fsl,tx-cal-45-dn-ohms: Integer [35-54]. Resistance (in ohms) of switchable
   high-speed trimming resistor connected in parallel with the 45 ohm resistor
   that terminates the DN output signal. Default: 45
-- fsl,tx-cal-45-dp-ohms: Integer [30-55]. Resistance (in ohms) of switchable
+- fsl,tx-cal-45-dp-ohms: Integer [35-54]. Resistance (in ohms) of switchable
   high-speed trimming resistor connected in parallel with the 45 ohm resistor
   that terminates the DP output signal. Default: 45
 - fsl,tx-d-cal: Integer [79-119]. Current trimming value (as a percentage) of