platform_data/mlxreg: Add new field for secured access

Extend structure 'mlxreg_core_data' with the field "secured". The
purpose of this field is to restrict access to some attributes, if
kernel is configured with security options, like:
LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY.
Access to some attributes, which for example, allow burning of some
hardware components, like FPGA, CPLD, SPI, etcetera can break the
system. In case user does not want to allow such access, it can disable
it by setting security options.

Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
Reviewed-by: Michael Shych <michaelsh@nvidia.com>
Link: https://lore.kernel.org/r/20211002093238.3771419-7-vadimp@nvidia.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

include/linux/platform_data/mlxreg.h

@@ -150,6 +150,7 @@ struct mlxreg_core_data {
 	bool attached;
 	u8 regnum;
 	u8 slot;
+	u8 secured;
 };
 
 /**