Config.in.legacy: drop legacy handling for BR2_PACKAGE_FIRMWARE_DDRFW_* options

These options were only added in commit
6bb7f3b81092e7005470c7d689a566dbc1d059c6, which was made after the
2020.05 release. So they are not part of any release at this point,
which makes legacy handling unnecessary.

Reported-by: Yann E. MORIN <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

Config.in.legacy

@@ -146,20 +146,6 @@ endif
 
 comment "Legacy options removed in 2020.08"
 
-config BR2_PACKAGE_FIRMWARE_DDRFW_LPDDR4
-	bool "i.MX LPDDR4 option renamed"
-	select BR2_LEGACY
-	help
-	  The option BR2_PACKAGE_FIRMWARE_DDRFW_LPDDR4 was renamed to
-	  BR2_PACKAGE_FIRMWARE_IMX_LPDDR4.
-
-config BR2_PACKAGE_FIRMWARE_DDRFW_DDR4
-	bool "i.MX DDR4 option renamed"
-	select BR2_LEGACY
-	help
-	  The option BR2_PACKAGE_FIRMWARE_DDRFW_DDR4 was renamed to
-	  BR2_PACKAGE_FIRMWARE_IMX_DDR4.
-
 config BR2_BINUTILS_VERSION_2_31_X
 	bool "binutils version 2.31.1 support removed"
 	select BR2_LEGACY