Grant table code is unused in shim mode, so there's no point in
building it in the first place for shim-exclusive mode.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
v2: Use UNCONSTRAINED.

--- a/xen/arch/x86/configs/pvshim_defconfig
+++ b/xen/arch/x86/configs/pvshim_defconfig
@@ -9,7 +9,6 @@ CONFIG_EXPERT=y
 # Disable features not used by the PV shim
 # CONFIG_XEN_SHSTK is not set
 # CONFIG_XEN_IBT is not set
-# CONFIG_GRANT_TABLE is not set
 # CONFIG_HYPFS is not set
 # CONFIG_BIGMEM is not set
 # CONFIG_KEXEC is not set
--- a/xen/common/Kconfig
+++ b/xen/common/Kconfig
@@ -15,6 +15,7 @@ config CORE_PARKING
 config GRANT_TABLE
 	bool "Grant table support" if EXPERT
 	default y
+	depends on UNCONSTRAINED
 	---help---
 	  Grant table provides a generic mechanism to memory sharing
 	  between domains. This shared memory interface underpins the