basealt.mk: add special power handling for e2k

There are two reasons to use/power on Elbrus:

1) current kernels generate "button" event for ACPI
   power button press instead of "button/power";
   systemd doesn't grok that, and acpid needs special
   configuration to (which needs to be fixed properly
   in said kernels but just not done yet -- mcst#6148);

2) installer-feature-e2k-power is useful on e2kv6
   as it configures e2k-pcs-cpufreq to autoload.

See-also: http://www.gnu.org/software/make/manual/make.html#Double_002dColon

PS: e2k-pcs-cpufreq uses to be builtin, *argh*

conf.d/basealt.mk

@@ -14,7 +14,7 @@ ifeq (,$(filter-out e2k%,$(ARCH)))
 distro/alt-workstation: mediaplayer = workstation/smplayer
 endif
 
-distro/alt-workstation: distro/.base +vmguest +wireless +efi \
+distro/alt-workstation:: distro/.base +vmguest +wireless +efi \
 	mixin/desktop-installer mixin/alt-workstation \
 	mixin/alt-workstation-install \
 	use/memtest use/rescue use/bootloader/grub use/luks \
@@ -63,6 +63,10 @@ endif	# e2k%
 	@$(call add,LIVE_LISTS,$(mediaplayer))
 	@$(call add,RESCUE_BOOTARGS,nomodeset vga=0)
 
+ifeq (,$(filter-out e2k%,$(ARCH)))
+distro/alt-workstation:: +power; @:
+endif
+
 endif	# distro
 
 ifeq (vm,$(IMAGE_CLASS))