sh: mach-systemh: Kill off dead board.

This code has been untouched since it was merged many years ago, and has
severely bitrotted since, suggesting that the board has no real users
left. Notice of intent to remove has been sent out over the last few
years, with no takers. Kill it off.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/Makefile

@@ -134,7 +134,6 @@ machdir-$(CONFIG_SH_HP6XX)			+= mach-hp6xx
 machdir-$(CONFIG_SH_DREAMCAST)			+= mach-dreamcast
 machdir-$(CONFIG_SH_SH03)			+= mach-sh03
 machdir-$(CONFIG_SH_RTS7751R2D)			+= mach-r2d
-machdir-$(CONFIG_SH_7751_SYSTEMH)		+= mach-systemh
 machdir-$(CONFIG_SH_EDOSK7705)			+= mach-edosk7705
 machdir-$(CONFIG_SH_HIGHLANDER)			+= mach-highlander
 machdir-$(CONFIG_SH_MIGOR)			+= mach-migor

arch/sh/boards/Kconfig

@@ -81,13 +81,6 @@ config SH_7343_SOLUTION_ENGINE
 	  Select 7343 SolutionEngine if configuring for a Hitachi
 	  SH7343 (SH-Mobile 3AS) evaluation board.
 
-config SH_7751_SYSTEMH
-	bool "SystemH7751R"
-	depends on CPU_SUBTYPE_SH7751R
-	help
-	  Select SystemH if you are configuring for a Renesas SystemH
-	  7751R evaluation board.
-
 config SH_HP6XX
 	bool "HP6XX"
 	select SYS_SUPPORTS_APM_EMULATION