util: resolve m5op name mismatching in m5op headers.

Two m5op, load_symbol and dist_toggle_sync are defined with
different name in C and asm version headers 'm5ops.h'
The m5ops are named to m5_load_symbol() and m5_dist_toggle_sync().

Change-Id: I9630d74f3fb95bc3dc5fa082778d8f6eaa49b3cb
Reviewed-on: https://gem5-review.googlesource.com/6481
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

util: Move m5op.h to the shared include directory

The header file with C declarations for m5ops is sometimes needed by
code outside of the util/m5 directory. Move this file to the shared
include directory and factor out flags to a generic asm header. Note
that applications that need to call m5ops still need to link with
libm5.a or implement their own trampolines.

Change-Id: I36a3f459ed71593e38b869dc2b1302c810f92276
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jose Marinho <jose.marinho@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/4265
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

util, m5: Use consistent naming for m5op C symbols

Rename m5op C symbols to be prefixed all lower case, separated by
underscore, and prefixed by m5. This avoids potential name clashes for
short names such as arm.

Change-Id: Ic42f94d8a722661ef96c151d627e31eeb2e51490
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jose Marinho <jose.marinho@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/4264
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

util: Move the m5ops.h file to a shared directory

The header file m5ops.h contains a list of constants that should be
shared between the simulator and utilities. Move this header file to a
new top-level directory for shared files and rename constants to make
them suitable for inclusion in the main simulator.

The structure of the shared include directory is as follows:

include/gem5: Files that can be included from C code.
include/gem5/asm: Files that can be included from assembly code.
asm/generic/: Files that aren't guest ISA specific
asm/${isa}/: Files that are guest ISA specific

Change-Id: I1aa511057bcaa80cc2d566109ff26581558c4a41
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jose Marinho <jose.marinho@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/4261
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>