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: d64008a8 "burying unused conditionals"
* HAVE_IRQ_WORK: 6147a9d8 "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>