sh: Kill off hs7751rvoip reference from arch/sh/Kconfig.

Remove reference to board deleted in commit 758e06ded4c48024835ef0a14627afcde2e25929
Signed-off-by: NAdrian McMenamin <adrian@mcmen.demon.co.uk>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

arch/sh/Kconfig

@@ -518,7 +518,6 @@ config SH_CAYMAN
 
 endmenu
 
-source "arch/sh/boards/renesas/hs7751rvoip/Kconfig"
 source "arch/sh/boards/renesas/rts7751r2d/Kconfig"
 source "arch/sh/boards/renesas/r7780rp/Kconfig"
 source "arch/sh/boards/magicpanelr2/Kconfig"