sunxi: Remove support for building "old-fashioned" fel binaries

The latest versions of the fel tool support loading normal u-boot builds
directly, and this is now the preferred way to use the fel boot method.

This commit removes support for the old deprecated standalone fel builds.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>

board/sunxi/Kconfig

@@ -194,24 +194,8 @@ config SYS_BOARD
 config SYS_SOC
 	default "sunxi"
 
-config SPL_FEL
-	bool "SPL/FEL mode support"
-	depends on SPL
-	default n
-	help
-	  This enables support for Fast Early Loader (FEL) mode. This
-	  allows U-Boot to be loaded to the board over USB by the on-chip
-	  boot rom. U-Boot should be sent in two parts: SPL first, with
-	  'fel write 0x2000 u-boot-spl.bin; fel exe 0x2000' then U-Boot with
-	  'fel write 0x4a000000 u-boot.bin; fel exe 0x4a000000'. This option
-	  shrinks the amount of SRAM available to SPL, so only enable it if
-	  you need FEL. Note that enabling this option only allows FEL to be
-	  used; it is still possible to boot U-Boot from boot media. U-Boot
-	  SPL detects when it is being loaded using FEL.
-
 config UART0_PORT_F
 	bool "UART0 on MicroSD breakout board"
-	depends on SPL_FEL
 	default n
 	---help---
 	Repurpose the SD card slot for getting access to the UART0 serial