Update sdmmc (thanks @gemarcano)

source/fatfs/sdmmc/delay.s

@@ -1,17 +1,15 @@
-// Copyright 2014 Normmatt
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
 .arm
-.global ioDelay
-.type   ioDelay STT_FUNC
+.global waitcycles
+.type   waitcycles STT_FUNC
 
-@ioDelay ( u32 us )
-ioDelay:
-	ldr r1, =0x18000000  @ VRAM
-1:
-	@ Loop doing uncached reads from VRAM to make loop timing more reliable
-	ldr r2, [r1]
-	subs r0, #1
-	bgt 1b
-	bx lr
+@waitcycles ( u32 us )
+waitcycles:
+	PUSH    {R0-R2,LR}
+	STR     R0, [SP,#4]
+	waitcycles_loop:
+		LDR     R3, [SP,#4]
+		SUBS    R2, R3, #1
+		STR     R2, [SP,#4]
+		CMP     R3, #0
+		BNE     waitcycles_loop
+	POP     {R0-R2,PC}