[MTD ONENAND] Remove unused MTD_ONENAND_SYNC_READ configuration

Now the bootloader configures the OneNAND sync. burst mode.
So we don't access Sync. burst mode related registers in kernel.
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

drivers/mtd/onenand/Kconfig

@@ -43,10 +43,4 @@ config MTD_ONENAND_OTP
 
 	  OTP block is fully-guaranteed to be a valid block.
 
-config MTD_ONENAND_SYNC_READ
-	bool "OneNAND Sync. Burst Read Support"
-	depends on ARCH_OMAP
-	help
-	  This enables support for Sync. Burst Read.
-
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