ARM updates

Due to the ABI we are using we have to use the earm architecture
moniker for the build system to behave correctly. This involves
then some headers to move around.

There is also a few related Makefile updates as well as minor
source code corrections.

include/arch/Makefile

@@ -1,5 +1,5 @@
 .include <bsd.own.mk>
 
-SUBDIR=	${MACHINE}
+SUBDIR=	${MACHINE_ARCH}
 
 .include <bsd.subdir.mk>

include/arch/earm/include/Makefile

@@ -1,5 +1,5 @@
 
-INCSDIR= /usr/include/arm
+INCSDIR= /usr/include/evbarm
 
 INCS= 	archconst.h archtypes.h diskparm.h elf.h interrupt.h \
 	ipcconst.h memory.h multiboot.h partition.h \

include/arch/earm/include/archtypes.h

@@ -17,6 +17,7 @@ struct cpu_info {
 	u32_t	implementer;
 	u32_t	part;
 	u32_t	variant;
+	u32_t	freq;		/* in MHz */
 	u32_t	revision;
 };