pinctrl: sh-pfc: sh7734: Remove bogus IPSR10 value

The IP10[5:3] field in Peripheral Function Select Register 10 has a
width of 3 bits, i.e. it allows programming one out of 8 different
configurations.
However, 9 values are provided instead of 8, overflowing into the
subsequent field in the register, and thus breaking the configuration of
the latter.

Fix this by dropping a bogus zero value.

Fixes: ac1ebc21 ("sh-pfc: Add sh7734 pinmux support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>