platform/x86: mlx-platform: remove an unused variable

platform/x86: mlx-platform: remove an unused variable

The only reference to the mlxplat_mlxcpld_psu[] array got removed,
so there is now a warning from clang:

drivers/platform/x86/mlx-platform.c:322:30: error: variable 'mlxplat_mlxcpld_psu' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration]
static struct i2c_board_info mlxplat_mlxcpld_psu[] = {

Remove the array as well and adapt the ARRAY_SIZE() call
accordingly.

Fixes: 912b341585e3 ("platform/x86: mlx-platform: Remove PSU EEPROM from MSN274x platform configuration")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Vadim Pasternak <vadimp@nvidia.com>
Link: https://lore.kernel.org/r/20201203223105.1195709-1-arnd@kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>