The pinmux bits for GPIO2-B0 to GPIO2-B6 actually have 2 bits width,
correct the bank flag for GPIO2-B. The pinmux bits for GPIO2-B7 is
recalculated so it remain unchanged.

The pinmux bits for those pins are not explicitly specified in RK3328
TRM, however we can get hint from pad name and its correspinding IOMUX
setting for pins in interface descriptions. The correspinding IOMIX
settings for GPIO2-B0 to GPIO2-B6 can be found in the same row next to
occurrences of following pad names in RK3328 TRM.

GPIO2-B0: IO_SPIclkm0_GPIO2B0vccio5
GPIO2-B1: IO_SPItxdm0_GPIO2B1vccio5
GPIO2-B2: IO_SPIrxdm0_GPIO2B2vccio5
GPIO2-B3: IO_SPIcsn0m0_GPIO2B3vccio5
GPIO2-B4: IO_SPIcsn1m0_FLASHvol_sel_GPIO2B4vccio5
GPIO2-B5: IO_ I2C2sda_TSADCshut_GPIO2B5vccio5
GPIO2-B6: IO_ I2C2scl_GPIO2B6vccio5

This fix has been tested on NanoPi R2S for fixing confliting pinmux bits
between GPIO2-B7 with GPIO2-B5.
Signed-off-by: Huang-Huang Bao <i@eh5.me>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Fixes: 3818e4a7 ("pinctrl: rockchip: Add rk3328 pinctrl support")
Link: https://lore.kernel.org/r/20240606125755.53778-2-i@eh5.meSigned-off-by: Linus Walleij <linus.walleij@linaro.org>