touch/common: fix flags in gpio_request() (v6.12 prep)

Linux commits [1] and [2] have cleaned up gpio flags and GPIOF_INIT_*
and GPIOF_DIR_* are gone. Drivers are meant to use GPIOF_OUT_INIT_* for
output gpios instead (and were required to do so for a long time).

This causes this driver to fail to compile:
    touch_bus_negotiator.c:438:5: error: use of undeclared identifier 'GPIOF_DIR_IN'; did you mean 'GPIOD_IN'?
      438 |                                 GPIOF_DIR_IN, "tbn,aoc2ap_gpio");
          |                                 ^~~~~~~~~~~~
          |                                 GPIOD_IN
    1 error generated.

Update the code accordingly.

Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4b2b0a2ce815 [1]
      ("gpiolib: legacy: Kill GPIOF_INIT_* definitions")
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8c045ca534d0 [2]
      ("gpiolib: legacy: Kill GPIOF_DIR_* definitions")
Test: TH
Bug: 369317190
Change-Id: I10c8c9d472bb5f38951fb9877b1ab2b71de8bd34
Signed-off-by: André Draszik <draszik@google.com>
Signed-off-by: Will McVicker <willmcvicker@google.com>