pci.c: assert MSIX table count <= config max

Assert that PCI devices discovered while booting the hypervisor do not
have more table entries than allowed by the compile-time configuration
(CONFIG_MAX_MSIX_TABLE_NUM).

The case were `msix.table_count` > `CONFIG_MAX_MSIX_TABLE_NUM` is fatal
since the init function in the handler for MSI-X (vmsix_init) only looks
at `table_count` when populating the table. Since
`CONFIG_MAX_MSIX_TABLE_NUM` is the max size of the table array entry in
the pci_msix struct. This will cause the msix handler to write outside of
the table array.

Tracked-On: #2624
Signed-off-by: Viktor Sjölind <vsjolind@luxoft.com>

hypervisor/hw/pci.c

@@ -352,6 +352,8 @@ static void pci_read_cap(struct pci_pdev *pdev)
 				pdev->msix.table_offset = table_info & ~PCIM_MSIX_BIR_MASK;
 				pdev->msix.table_count = (msgctrl & PCIM_MSIXCTRL_TABLE_SIZE) + 1U;
 
+				ASSERT(pdev->msix.table_count <= CONFIG_MAX_MSIX_TABLE_NUM);
+
 				/* Copy MSIX capability struct into buffer */
 				for (idx = 0U; idx < len; idx++) {
 					pdev->msix.cap[idx] = (uint8_t)pci_pdev_read_cfg(pdev->bdf, offset + idx, 1U);