Compile ide/macio only once

Replace TARGET_PAGE_SIZE with 4096. Make byte swapping unconditional
since PPC is big endian.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
diff --git a/Makefile.target b/Makefile.target
index 51ddbb9..ee2cff0 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -190,7 +190,7 @@
 obj-i386-y += debugcon.o multiboot.o
 
 # shared objects
-obj-ppc-y = ppc.o ide/macio.o
+obj-ppc-y = ppc.o
 obj-ppc-y += vga.o dma.o openpic.o
 # PREP target
 obj-ppc-y += pckbd.o i8259.o mc146818rtc.o