ARC: Kconfig cleanup tracking cross-arch Kconfig pruning in merge window

Since ARC port was not yet upstream, we missed a bunch of cross-arch
Kconfig removals:

* GENERIC_SIGALTSTACK: d64008a "burying unused conditionals"
* HAVE_IRQ_WORK: 6147a9d "irq_work: Remove CONFIG_HAVE_IRQ_WORK"
* ARCH_NO_VIRT_TO_BUS: e0cf2ef484 "arch Kconfig: centralise
                                   CONFIG_ARCH_NO_VIRT_TO_BUS"

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/Kconfig

@@ -19,13 +19,11 @@ config ARC
 	select GENERIC_KERNEL_EXECVE
 	select GENERIC_KERNEL_THREAD
 	select GENERIC_PENDING_IRQ if SMP
-	select GENERIC_SIGALTSTACK
 	select GENERIC_SMP_IDLE_THREAD
 	select HAVE_ARCH_KGDB
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_GENERIC_HARDIRQS
 	select HAVE_IOREMAP_PROT
-	select HAVE_IRQ_WORK
 	select HAVE_KPROBES
 	select HAVE_KRETPROBES
 	select HAVE_MEMBLOCK
@@ -76,9 +74,6 @@ config HAVE_LATENCYTOP_SUPPORT
 config NO_DMA
 	def_bool n
 
-config ARCH_NO_VIRT_TO_BUS
-	def_bool y
-
 source "init/Kconfig"
 source "kernel/Kconfig.freezer"