MIPS: Kconfig: remove "config MIPS_BOARDS_GEN"

The Kconfig symbol MIPS_BOARDS_GEN is unused since v2.6.27. It should
now be removed.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Patchwork: http://patchwork.linux-mips.org/patch/5063/Acked-by: John Crispin <blogic@openwrt.org>

arch/mips/Kconfig

@@ -306,7 +306,6 @@ config MIPS_MALTA
 	select HW_HAS_PCI
 	select I8253
 	select I8259
-	select MIPS_BOARDS_GEN
 	select MIPS_BONITO64
 	select MIPS_CPU_SCACHE
 	select PCI_GT64XXX_PCI0
@@ -342,7 +341,6 @@ config MIPS_SEAD3
 	select DMA_NONCOHERENT
 	select IRQ_CPU
 	select IRQ_GIC
-	select MIPS_BOARDS_GEN
 	select MIPS_CPU_SCACHE
 	select MIPS_MSC
 	select SYS_HAS_CPU_MIPS32_R1
@@ -1079,9 +1077,6 @@ config IRQ_GT641XX
 config IRQ_GIC
 	bool
 
-config MIPS_BOARDS_GEN
-	bool
-
 config PCI_GT64XXX_PCI0
 	bool