fix "uname -p" on mips n32.

this has been returning "mipsn64eb" on my edgerouter4 with the
32 bit uname binary.

introduce o32, n32, and n64 versions of MACHINE_ARCH, and use
them appropriately in PROC_MACHINE_ARCH32(). now o32, n32 and
n64 "uname -p" all return different values.

#define<tab>
Nuke trailing whitespace.

Allow architectures to define a macro PROC_MACHINE_ARCH(P) and
PROC_MACHINE_ARCH32(P) to override the value for sysctl hw.machine_arch
(native and netbsd32 commpat resp.).

Use these for arm and mips instead of the (not working, noisy, in case
of arm) sysctl override and #ifdef __mips__ in architecture neutral
code.

machine_arch on mips depends on the ABI so we need a routine to return
the right value.

branches: 1.3.2; 1.3.16;
Remove COMPAT_SA / KERN_SA. Welcome to 6.99.3!
Approved by core@.

branches: 1.2.4; 1.2.14; 1.2.18;
Merge from matt-nb5-mips64
Merge mips-specific arch files.

branches: 1.1.2;
file netbsd32_machdep.h was initially added on branch matt-nb5-mips64.

#define<tab>
Nuke trailing whitespace.

Allow architectures to define a macro PROC_MACHINE_ARCH(P) and
PROC_MACHINE_ARCH32(P) to override the value for sysctl hw.machine_arch
(native and netbsd32 commpat resp.).

Use these for arm and mips instead of the (not working, noisy, in case
of arm) sysctl override and #ifdef __mips__ in architecture neutral
code.

machine_arch on mips depends on the ABI so we need a routine to return
the right value.

branches: 1.3.2; 1.3.16;
Remove COMPAT_SA / KERN_SA. Welcome to 6.99.3!
Approved by core@.

branches: 1.2.4; 1.2.14; 1.2.18;
Merge from matt-nb5-mips64
Merge mips-specific arch files.

branches: 1.1.2;
file netbsd32_machdep.h was initially added on branch matt-nb5-mips64.

Allow architectures to define a macro PROC_MACHINE_ARCH(P) and
PROC_MACHINE_ARCH32(P) to override the value for sysctl hw.machine_arch
(native and netbsd32 commpat resp.).

Use these for arm and mips instead of the (not working, noisy, in case
of arm) sysctl override and #ifdef __mips__ in architecture neutral
code.

machine_arch on mips depends on the ABI so we need a routine to return
the right value.

branches: 1.3.2; 1.3.16;
Remove COMPAT_SA / KERN_SA. Welcome to 6.99.3!
Approved by core@.

branches: 1.2.4; 1.2.14; 1.2.18;
Merge from matt-nb5-mips64
Merge mips-specific arch files.

branches: 1.1.2;
file netbsd32_machdep.h was initially added on branch matt-nb5-mips64.