x86/platform/uv: Fix kdump for UV

x86/platform/uv: Fix kdump for UV

With uv_nmi.action=kdump on the boot line, "power nmi" does not kdump.
Instead it produces backtraces (the default "dump" action).

One line from upstream commit 2965faa5e03d ("kexec: split kexec_load
syscall from kexec core code") was inadvertantly applied to
arch/x86/platform/uv/uv_nmi.c, but the rest of the commit is
missing. The UEK kernel does not have any of the other
CONFIG_KEXEC_CORE related changes in it, so this breaks uv_nmi

Orabug: 27031345

Signed-off-by: Kirtikar Kashyap <kirtikar.kashyap@oracle.com>
Reviewed-by: Brian Maly <brian.maly@oracle.com>