jh7110_pcie.c: add empty PIC methods to conform conventions

This commit updates the driver code to conform with an undocumented
convention which says that certain functions need always be implemented
together regardless of their content (or lack of). It's been said that
unimplemented KOBJ methods become stubs which return ENXIO so this
commit does not imply a functional change.

Reviewed by:	mhorne
Differential Revision:	https://reviews.freebsd.org/D52042

sys/riscv/starfive/jh7110_pcie.c

@@ -482,6 +482,16 @@ jh7110_pcie_msi_enable_intr(device_t dev, struct intr_irqsrc *isrc)
 	jh7110_pcie_msi_mask(dev, isrc, false);
 }
 
+static void
+jh7110_pcie_msi_post_filter(device_t dev, struct intr_irqsrc *isrc)
+{
+}
+
+static void
+jh7110_pcie_msi_post_ithread(device_t dev, struct intr_irqsrc *isrc)
+{
+}
+
 static void
 jh7110_pcie_msi_pre_ithread(device_t dev, struct intr_irqsrc *isrc)
 {
@@ -1008,6 +1018,8 @@ static device_method_t jh7110_pcie_methods[] = {
 	/* Interrupt controller interface */
 	DEVMETHOD(pic_enable_intr,	jh7110_pcie_msi_enable_intr),
 	DEVMETHOD(pic_disable_intr,	jh7110_pcie_msi_disable_intr),
+	DEVMETHOD(pic_post_filter,	jh7110_pcie_msi_post_filter),
+	DEVMETHOD(pic_post_ithread,	jh7110_pcie_msi_post_ithread),
 	DEVMETHOD(pic_pre_ithread,	jh7110_pcie_msi_pre_ithread),
 
 	/* OFW bus interface */