MAINTAINERS: fixup file entries for "SIMTEC EB2410ITX (BAST)"

Add the correct files for the Simtec BAST machine, ensuring the IDE and
IRQ routing are added, and move to the machine specific file instead of
trying to catch all of arch/arm/mach-s3c2410

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Cc: Simtec Linux Team <linux@simtec.co.uk>
Cc: Simtec Support <support@simtec.co.uk>
Cc: Jack Stone <jwjstone@fastmail.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>