pinctrl: sh-pfc: sh7734: Add missing IPSR11 field

The Peripheral Function Select Register 11 contains 3 reserved bits and
15 variable-width fields, but the variable field descriptor does not
contain the 3-bit field IP11[25:23].

Fixes: 856cb4bb ("sh: Add support pinmux for SH7734")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>