x86/pvshim: disable PDX compression in PV shim defconfig

There's no need for PDX compression given the memory map provided by Xen
to guests is contiguous, turn off the feature by default in the PV shim
defconfig.

Reported-by: Jan Beulich <jbeulich@suse.com>
Fixes: c5c45bcbd6 ("pdx: introduce a new compression algorithm based on region offsets")
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

xen/arch/x86/configs/pvshim_defconfig

@@ -7,6 +7,7 @@ CONFIG_PV_SHIM_EXCLUSIVE=y
 CONFIG_NR_CPUS=32
 CONFIG_EXPERT=y
 # Disable features not used by the PV shim
+CONFIG_PDX_NONE=y
 # CONFIG_XEN_SHSTK is not set
 # CONFIG_XEN_IBT is not set
 # CONFIG_GRANT_TABLE is not set