SD_QUIRKS: Document the SD_QUIRKS bootloader property

Author: timg236

documentation/asciidoc/computers/raspberry-pi/eeprom-bootloader.adoc

@@ -151,6 +151,24 @@ The number of times that SD boot will be retried after failure before moving to
 
 `-1` means infinite retries.
 
+Default: `0`
+
+[[SD_QUIRKS]]
+==== `SD_QURIKS`
+
+The `SD_QUIRKS` property provides a set of options to support device bringup and workaround interoperability issues.
+
+The flags are implemented as a bit-field. Undefined bits are reserved for future use and should be set to zero.
+
+[cols="1m,3"]
+|===
+| Value | Behaviour
+
+| 0x1
+| Disable SD High Speed modes. The card clock is limited to 12.5 MHz
+|===
+
+
 Default: `0`
 
 [[NET_BOOT_MAX_RETRIES]]