Calling gpio_request() prior to its usage is now mandatory.

This fixes the following GPIO errors:

U-Boot SPL 2022.01-rc3-00067-g7a5be871c0ec (Dec 18 2021 - 17:45:07 -0300)
Trying to boot from MMC1

U-Boot 2022.01-rc3-00067-g7a5be871c0ec (Dec 18 2021 - 17:45:07 -0300)

CPU:   Freescale i.MX6Q rev1.2 at 792 MHz
Reset cause: WDOG
Model: Udoo i.MX6 Quad Board
Board: Udoo Quad
DRAM:  1 GiB
MMC:   FSL_SDHC: 2
Loading Environment from MMC... OK
In:    serial
Out:   serial
Err:   serial
gpio@20a0000: set_dir_flags: error: gpio GPIO2_31 not reserved
gpio@20a4000: set_dir_flags: error: gpio GPIO3_23 not reserved
gpio@20b0000: set_dir_flags: error: gpio GPIO6_24 not reserved
gpio@20b0000: set_dir_flags: error: gpio GPIO6_25 not reserved
gpio@20b0000: set_dir_flags: error: gpio GPIO6_27 not reserved
gpio@20b0000: set_dir_flags: error: gpio GPIO6_28 not reserved
gpio@20b0000: set_dir_flags: error: gpio GPIO6_29 not reserved
gpio@20a4000: set_value: error: gpio GPIO3_23 not reserved
Net:   Could not get PHY for FEC0: addr -2
No ethernet found.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Peter Robinson <pbrobinson@gmail.com>