[SRU][J:linux-bluefield][PATCH v1 0/1] UBUNTU: SAUCE: gpio-mlxbf3: support valid mask

[Asmaa Mnebhi]

BugLink: https://bugs.launchpad.net/bugs/2038868

SRU Justification:

[Impact]

After syncing up the gpio-mlxbf3.c driver with the upstreamed version,
we dropped the use of the valid_mask variable because kernels greater
or equal to 6.2.0 dont need it.
This is no longer needed in kernel versions >= 6.2.0 because valid_mask
is populated by core gpio code.
5.15 kernel doesnt support that feature so we still need to explicitly
define valid_mask like we did before.
This doesnt impact the functionality of the GPIO driver but it is a
security breach as it doesnt restrict the access to only gpios defined
in the acpi table by valid_mask.

[Fix]

* define valid_mask and init_valid_mask

[Test Case]

* Make sure that the user (libgpiod) cannot access any other gpio besides
  0->4 (gpiochip0) and 22-23 in gpiochip1.

[Regression Potential]

no known regression.