PLDM: Mark all _current attributes as readonly

- The _current attributes are supposed to be only set by HOST and
NOT by any redfish client, so by marking them as readonly
we would deny customers/redfish client to do PATCH operations
on _current attributes.

- List of attribute modified as readOnly:
hb_cap_freq_mhz_request_current
hb_field_core_override_current
hb_host_usb_enablement_current
hb_huge_page_size_current
hb_key_clear_request_current
hb_lateral_cast_out_mode_current
hb_memory_mirror_mode_current
hb_memory_region_size_current
hb_mfg_flags_current
hb_number_huge_pages_current
hb_power_limit_enable_current
hb_proc_favor_aggressive_prefetch_current
hb_tpm_required_current
pvm_create_default_lpar_current
pvm_default_os_type_current
pvm_os_boot_type_current
pvm_rpa_boot_mode_current
pvm_stop_at_standby_current
pvm_vtpm_current

Tested:
- Tried to change attribute using redfish command which is blocked now.
- Tried to change attribute using pldmtool command which is working fine.

Change-Id: I879266d73e033dd55ff6c61e414bea2fd617bbef
Signed-off-by: Patel-Kamalkumar <kamalkumar.patel@ibm.com>
diff --git a/oem/ibm/configurations/bios/integer_attrs.json b/oem/ibm/configurations/bios/integer_attrs.json
index cce37b5..6dfdc51 100644
--- a/oem/ibm/configurations/bios/integer_attrs.json
+++ b/oem/ibm/configurations/bios/integer_attrs.json
@@ -51,6 +51,7 @@
             "upper_bound": 65535,
             "scalar_increment": 1,
             "default_value": 0,
+            "readOnly": true,
             "helpText": "Specifies the number of huge pages available for memory management for the current IPL. Do not set this attribute directly; set hb_number_huge_pages instead.",
             "displayName": "Number Huge Pages (current)"
         },
@@ -69,6 +70,7 @@
             "upper_bound": 255,
             "scalar_increment": 1,
             "default_value": 0,
+            "readOnly": true,
             "helpText": "Specifies the size of huge pages, 0 = 16GB, for the current IPL. Do not set this attribute directly; set hb_huge_page_size instead.",
             "displayName": "Huge Page Size (current)"
         },
@@ -87,6 +89,7 @@
             "upper_bound": 255,
             "scalar_increment": 1,
             "default_value": 0,
+            "readOnly": true,
             "helpText": "The maximum number of cores to activate where 0 being to activate all available cores. Value applicable for the current IPL. Do not set this attribute directly; set hb_field_core_override instead.",
             "displayName": "Field Core Override (current)"
         },
@@ -179,6 +182,7 @@
             "upper_bound": 4294967295,
             "scalar_increment": 1,
             "default_value": 0,
+            "readOnly": true,
             "helpText": "Specifies the desired frequency across all chips in the system.  Do not set this attribute directly; set hb_cap_freq_mhz_request instead.",
             "displayName": "Requested Core Freq MHZ (current)"
         }