build: hide kmod-zram config unless enabled

Currently the zram default compressor choice is displayed whether or not
zram is activated. Since the default choice is lzo-rle, this adds a
false dependency on kmod-lib-lzo.
With this patch, the choice options appear only when activating zram.

Signed-off-by: Rani Hod <rani.hod@gmail.com>
(cherry picked from commit 62ada26de2)

package/kernel/linux/modules/other.mk

@@ -1013,6 +1013,7 @@ define KernelPackage/zram/description
 endef
 
 define KernelPackage/zram/config
+  if PACKAGE_kmod-zram
     choice
       prompt "ZRAM Default compressor"
       default ZRAM_DEF_COMP_LZORLE
@@ -1038,6 +1039,7 @@ define KernelPackage/zram/config
             select PACKAGE_kmod-lib-zstd
 
     endchoice
+  endif
 endef
 
 $(eval $(call KernelPackage,zram))