Merge: of: reserved_mem: Restructure how the reserved memory regions are processed

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-10/-/merge_requests/1688

# Merge Request Required Information

## Summary of Changes

This MR backports a number of upstream commits to the OpenFirmware reserved memory handling code to remove the hard limits of 64 regions that we've hit on some ARM SoCs, for example the Qualcomm 8775.

## Approved Development Ticket(s)
JIRA: https://issues.redhat.com/browse/RHEL-125402

Signed-off-by: Maxime Ripard <mripard@redhat.com>

Approved-by: Jerry Snitselaar <jsnitsel@redhat.com>
Approved-by: Eric Chanudet <echanude@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: CKI GitLab Kmaint Pipeline Bot <26919896-cki-kmaint-pipeline-bot@users.noreply.gitlab.com>

Author: CKI KWF Bot

drivers/of/fdt.c

@@ -511,8 +511,6 @@ void __init early_init_fdt_scan_reserved_mem(void)
 			break;
 		memblock_reserve(base, size);
 	}
-
-	fdt_init_reserved_mem();
 }
 
 /**
@@ -1212,6 +1210,9 @@ void __init unflatten_device_tree(void)
 {
 	void *fdt = initial_boot_params;
 
+	/* Save the statically-placed regions in the reserved_mem array */
+	fdt_scan_reserved_mem_reg_nodes();
+
 	/* Don't use the bootloader provided DTB if ACPI is enabled */
 	if (!acpi_disabled)
 		fdt = NULL;

drivers/of/of_private.h

@@ -9,6 +9,7 @@
  */
 
 #define FDT_ALIGN_SIZE 8
+#define MAX_RESERVED_REGIONS    64
 
 /**
  * struct alias_prop - Alias property in 'aliases' node
@@ -183,7 +184,7 @@ static inline struct device_node *__of_get_dma_parent(const struct device_node *
 #endif
 
 int fdt_scan_reserved_mem(void);
-void fdt_init_reserved_mem(void);
+void __init fdt_scan_reserved_mem_reg_nodes(void);
 
 bool of_fdt_device_is_available(const void *blob, unsigned long node);