docs: kernel-parameters: Move gpio-mockup for alphabetic order

All other sections are ordered alphabetically so do the same for
gpio-mockup.

Fixes: 0f98dd1b ("gpio/mockup: add virtual gpio device")
Signed-off-by: Alexander Dahl <ada@thorsis.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Documentation/admin-guide/kernel-parameters.txt

@@ -1461,6 +1461,10 @@
 			Don't use this when you are not running on the
 			android emulator
 
+	gpio-mockup.gpio_mockup_ranges
+			[HW] Sets the ranges of gpiochip of for this device.
+			Format: <start1>,<end1>,<start2>,<end2>...
+
 	gpt		[EFI] Forces disk with valid GPT signature but
 			invalid Protective MBR to be treated as GPT. If the
 			primary GPT is corrupted, it enables the backup/alternate
@@ -1484,10 +1488,6 @@
 			Format: <unsigned int> such that (rxsize & ~0x1fffc0) == 0.
 			Default: 1024
 
-	gpio-mockup.gpio_mockup_ranges
-			[HW] Sets the ranges of gpiochip of for this device.
-			Format: <start1>,<end1>,<start2>,<end2>...
-
 	hardlockup_all_cpu_backtrace=
 			[KNL] Should the hard-lockup detector generate
 			backtraces on all cpus.