i2c: mlxbf: Allow build with COMPILE_TEST

Extend the Kconfig dependency to include COMPILE_TEST so the
Mellanox BlueField I2C driver can be built on non-ARM64 platforms
for compile testing purposes.

Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Cc: Khalil Blaiech <kblaiech@nvidia.com>
Cc: Asmaa Mnebhi <asmaa@nvidia.com>
Link: https://lore.kernel.org/r/20250505215854.2896383-1-andi.shyti@kernel.org