arm64: asm-offsets: remove VM_EXEC and PAGE_SZ

arm64: asm-offsets: remove VM_EXEC and PAGE_SZ

The VM_EXEC definition duplicates the common VM_EXEC definition from
<linux/mm.h>. The common definition cannot safely be included by
assembly code but currently we don't need to use VM_EXEC in assembly.

The PAGE_SZ definition duplicates arm64's definition of PAGE_SIZE from
<asm/page-def.h> which can safely be included from assembly code and
should be used directly.

Remove the duplicate definitions.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241007123921.549340-6-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>