metag: Remove _STK_LIM_MAX override

Meta overrode _STK_LIM_MAX (the default RLIMIT_STACK hard limit) to
256MB, apparently in an attempt to prevent setup_arg_pages's
STACK_GROWSUP code from choosing the maximum stack size of 1GB, which is
far too large for Meta's limited virtual address space and hits a BUG_ON
(stack_top is usually 0x3ffff000).

However the commit "metag: Reduce maximum stack size to 256MB" reduces
the absolute stack size limit to a safe value for metag. This allows the
default _STK_LIM_MAX override to be removed, bringing the default
behaviour in line with all other architectures. Parisc in particular
recently removed their override of _STK_LIMT_MAX in commit e0d8898d76a7
(parisc: remove _STK_LIM_MAX override) since it subtly affects stack
allocation semantics in userland. Meta's uapi/asm/resource.h can now be
removed and switch to using generic-y.

Suggested-by: Helge Deller <[e-mail]>
Signed-off-by: James Hogan <[e-mail]>
Cc: [e-mail]
Cc: John David Anglin <[e-mail]>

arch/metag/include/uapi/asm/Kbuild

···
 header-y += byteorder.h
 header-y += ech.h
 header-y += ptrace.h
-header-y += resource.h
 header-y += sigcontext.h
 header-y += siginfo.h
 header-y += swab.h
 header-y += unistd.h
 
 generic-y += mman.h
+generic-y += resource.h
 generic-y += setup.h

arch/metag/include/uapi/asm/resource.h

···
-#ifndef _UAPI_METAG_RESOURCE_H
-#define _UAPI_METAG_RESOURCE_H
-
-#define _STK_LIM_MAX    (1 << 28)
-#include <asm-generic/resource.h>
-
-#endif /* _UAPI_METAG_RESOURCE_H */