arm64: Kconfig: drop KAISER reference from KPTI option description

KAISER is a reference to the KASLR hardening technique that already
existed before Meltdown happened, and by now, it is sufficiently obscure
that mentioning it does not actually clarify anything. So remove this
reference, and replace it with KPTI.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20231127120049.2258650-8-ardb@google.comSigned-off-by: Will Deacon <will@kernel.org>

arch/arm64/Kconfig

@@ -1549,7 +1549,7 @@ config ARCH_FORCE_MAX_ORDER
 	  Don't change if unsure.
 
 config UNMAP_KERNEL_AT_EL0
-	bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
+	bool "Unmap kernel when running in userspace (KPTI)" if EXPERT
 	default y
 	help
 	  Speculation attacks against some high-performance processors can