H8/300: Fix misnamed "CONFIG_BLKDEV_RESERVE_ADDRESS" Kconfig variable

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Acked-by: Satyam Sharma <satyam@infradead.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>