ARM: mm: export default vmalloc base address

maillist inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8KNA9
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git/commit/?h=arm-kaslr-latest&id=c3ae0029ea41f4a26a40f592062155412d1b6d07



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In order for the EFI stub to be able to decide over what range to
randomize the load address of the kernel, expose the definition of
the default vmalloc base address as VMALLOC_DEFAULT_BASE.

Cc: Russell King <linux@armlinux.org.uk>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Felix Fu <fuzhen5@huawei.com>