[MIPS] Allow selection of KGDB only on platforms where it's supported.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 46fa5ca..c6f74f1 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -144,6 +144,7 @@
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_BIG_ENDIAN
+	select SYS_SUPPORTS_KGDB
 	help
 	  The eXcite is a smart camera platform manufactured by
 	  Basler Vision Technologies AG
@@ -210,6 +211,7 @@
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_BIG_ENDIAN
+	select SYS_SUPPORTS_KGDB
 	help
 	  This is an evaluation board based on the Galileo GT-64120
 	  single-chip system controller that contains a MIPS R5000 compatible
@@ -374,6 +376,7 @@
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_BIG_ENDIAN
+	select SYS_SUPPORTS_KGDB
 	help
 	  The Jaguar ATX is a MIPS-based Single Board Computer (SBC) made by
 	  Momentum Computer <http://www.momenco.com/>.
@@ -391,6 +394,7 @@
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_BIG_ENDIAN
+	select SYS_SUPPORTS_KGDB
 	help
 	  The Ocelot is a MIPS-based Single Board Computer (SBC) made by
 	  Momentum Computer <http://www.momenco.com/>.
@@ -480,6 +484,8 @@
 	select SYS_HAS_CPU_R5432
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select SYS_SUPPORTS_64BIT_KERNEL if EXPERIMENTAL
+	select SYS_SUPPORTS_KGDB
+	select SYS_SUPPORTS_KGDB
 	select SYS_SUPPORTS_LITTLE_ENDIAN
 	help
 	  This enables support for the R5432-based NEC DDB Vrc-5477,
@@ -508,6 +514,7 @@
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_BIG_ENDIAN
 	select SYS_SUPPORTS_HIGHMEM
+	select SYS_SUPPORTS_KGDB
 	select SYS_SUPPORTS_SMP
 	help
 	  Yosemite is an evaluation board for the RM9000x2 processor
@@ -584,6 +591,7 @@
 	select SYS_HAS_CPU_R10000
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_BIG_ENDIAN
+	select SYS_SUPPORTS_KGDB
 	select SYS_SUPPORTS_NUMA
 	select SYS_SUPPORTS_SMP
 	select GENERIC_HARDIRQS_NO__DO_IRQ
@@ -633,6 +641,7 @@
 	select SYS_HAS_CPU_SB1
 	select SYS_SUPPORTS_BIG_ENDIAN
 	select SYS_SUPPORTS_HIGHMEM
+	select SYS_SUPPORTS_KGDB
 	select SYS_SUPPORTS_LITTLE_ENDIAN
 
 config SIBYTE_SENTOSA
@@ -773,6 +782,7 @@
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_LITTLE_ENDIAN
 	select SYS_SUPPORTS_BIG_ENDIAN
+	select SYS_SUPPORTS_KGDB
 	select TOSHIBA_BOARDS
 	select GENERIC_HARDIRQS_NO__DO_IRQ
 	help
@@ -793,6 +803,7 @@
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select SYS_SUPPORTS_LITTLE_ENDIAN
 	select SYS_SUPPORTS_BIG_ENDIAN
+	select SYS_SUPPORTS_KGDB
 	select TOSHIBA_BOARDS
 	select GENERIC_HARDIRQS_NO__DO_IRQ
 	help
@@ -959,6 +970,7 @@
 
 config DDB5XXX_COMMON
 	bool
+	select SYS_SUPPORTS_KGDB
 
 config MIPS_BOARDS_GEN
 	bool
@@ -1007,6 +1019,7 @@
 	select SYS_HAS_CPU_MIPS32_R1
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select SYS_SUPPORTS_APM_EMULATION
+	select SYS_SUPPORTS_KGDB
 
 config PNX8550
 	bool
@@ -1019,6 +1032,7 @@
 	select SYS_HAS_CPU_MIPS32_R1
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select GENERIC_HARDIRQS_NO__DO_IRQ
+	select SYS_SUPPORTS_KGDB
 
 config SWAP_IO_SPACE
 	bool